Gastrointestinal system at a glance, the keshav, satish, bailey, adam

The Gastrointestinal System at a Glance This new edition is also available as an e-book For more details, please see www.wiley.com/buy/9781405150910 or scan this QR code The Gastrointestinal System at a Glance Satish Keshav Consultant Gastroenterologist John Radcliffe Hospital Oxford, UK Adam Bailey Consultant Gastroenterologist John Radcliffe Hospital Oxford, UK Second edition A John Wiley & Sons, Ltd., Publication This edition first published 2013 © 2013 by Blackwell Publishing Ltd Previous edition 2004 Blackwell Publishing was acquired by John Wiley & Sons in February 2007 Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical and Medical business to form Wiley-Blackwell Registered office: John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 350 Main Street, Malden, MA 02148-5020, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www wiley.com/wiley-blackwell The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988 All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher Designations used by companies to distinguish their products are often claimed as trademarks All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners The publisher is not associated with any product or vendor mentioned in this book This publication is designed to provide accurate and authoritative information in regard to the subject matter covered It is sold on the understanding that the publisher is not engaged in rendering professional services If professional advice or other expert assistance is required, the services of a competent professional should be sought Library of Congress Cataloging-in-Publication Data Keshav, Satish   The gastrointestinal system at a glance / Satish Keshav, Adam Bailey – 2nd ed    p ; cm – (At a glance series)   Includes bibliographical references and index   ISBN 978-1-4051-5091-0 (pbk : alk paper)   I.  Bailey, Adam, Dr.  II.  Title.  III.  Series: At a glance series (Oxford, England)   [DNLM:  1.  Digestive System.  2.  Digestive System Diseases.  WI 100]   612.3'2–dc23 2012007480 A catalogue record for this book is available from the British Library Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic books Cover design: Meaden Creative Set in 9/11.5 pt Times by Toppan Best-set Premedia Limited 1  2013 Contents Preface  Acknowledgements  List of abbreviations  25 Hepatic metabolic function  58 26 Hepatic synthetic function  60 27 Hepatic detoxification and excretion  62 Introduction and overview  Part 3  Disorders and diseases 28 Nausea and vomiting  64 29 Diarrhoea  66 30 Constipation  68 31 Functional disorders and irritable bowel syndrome  70 32 Gastro-oesophageal reflux and hiatus hernia  72 33 Peptic ulcer and Helicobacter pylori  74 34 Gastroenteritis and food poisoning  76 35 Gastrointestinal system infections  78 36 Ulcerative colitis and Crohn’s disease  80 37 Coeliac disease  82 38 Obesity and malnutrition  84 39 Colon and rectal cancer  86 40 Gastrointestinal, pancreatic and liver tumours  88 41 Haemorrhoids and anorectal disease  90 42 Gallstones and pancreatitis  92 43 Hepatitis and acute liver disease  94 44 Cirrhosis and chronic liver disease  96 Part 1  Structure and function   Mouth and teeth  10   Salivary glands  12   Tongue and pharynx  14   Oesophagus  16   Stomach  18   Duodenum  20   Pancreas  22   Liver  24   Biliary system  26 10 Hepatic portal system  28 11 Jejunum and ileum  30 12 Caecum and appendix  32 13 Colon  34 14 Rectum and anus  36 Part 2  Integrated function 15 Embryology  38 16 Enteric motility  40 17 Enteric endocrine system  42 18 Enteric and autonomic nerves  44 19 Mucosal immune system  46 20 Digestion and absorption  48 21 Digestion of carbohydrates, proteins and fats  50 22 Digestion of vitamins and minerals  52 23 Nutrition  54 24 Fluid and electrolyte balance  56 Part 4  Diagnosis and treatment 45 History, examination and tests  98 46 Diagnostic endoscopy  100 47 Therapeutic endoscopy  102 48 Radiology and imaging  104 49 Functional tests  106 50 Pharmacotherapy  108 51 Gastrointestinal surgery  110 Index  112 Companion website A companion website is available at: www.ataglanceseries.com/gastro featuring: •  Interactive multiple-choice questions •  Flashcards of key figures with interactive on/off labels Contents  Preface Organization of the book The Gastrointestinal System at a Glance is organized in four parts, each starting with a structural and functional overview of the main components of the system and followed by chapters dealing with integrated gastrointestinal function The clinical relevance of aspects of anatomy, physiology and function is discussed in each chapter in order to highlight the practical importance of each subject The third and fourth sections are more clinical, covering the most important gastrointestinal and hepatobiliary diseases and the major aspects of diagnosis and treatment Endoscopy and radiology are described in dedicated chapters Self-assessment questions on the accompanying website are all based on the text, and can be used to check understanding and recall How to use this book This book offers a visual and graphic scaffold for further detailed study The aim is to provide pictures that will illustrate concepts and make them more memorable Thus, the book can be read before starting on coursework, annotated with additional details from lectures, tutorials and self-directed study, and then used for revision before examinations It will therefore be useful for students approaching a subject for the first time, particularly as part of an integrated systems-based medical curriculum The diagrams, many of which will also be available as online flashcards, should trigger recall of facts that might otherwise be lost in plain text Anatomical and clinical detail The anatomical diagrams are representations, and not exact reproductions, to illustrate how structure supports function, rather than to provide exact detail For more thorough anatomy, students may use Anatomy at a Glance, also available in this series Similarly, specific diseases are discussed to demonstrate pathogenic mechanisms and general principles, rather than to provide exhaustive detail This book should be used to understand the normal physiology, how it goes wrong in disease, and the principles underlying modern clinical practice in gastroenterology and hepatology Satish Keshav Adam Bailey Acknowledgements We thank all the staff at Wiley-Blackwell Publishing, particularly Martin Sugden, Fiona Pattision, Ben Townsend, Martin Davies, and Karen Moore, who encouraged us through the gestation of 6  Preface this edition Professor Darrell Evans of Brighton and Sussex Medicine School co-authored the chapter on Embryology, for which we are grateful List of abbreviations ACh AFP AIDS ALP ALT ANCA APC 5ASA ASCA AST ATP ATPase AVM BAT BEE βHCG BMI BMR BSE Ca2+ cAMP CCD CCK CD CE CEA CFTR cGMP CGRP Cl− CLO CMV CO2 CoA CRC CRP CT CTC CTZ Cu2+ DA DMT DNA ECL EHEC EPEC ERCP ESR ETEC EUS FAP Fe2+ Fe3+ FIT GABA GIST γGT GTN H+ H2O H2R HCl HCO3− HDL acetylcholine α-fetoprotein acquired immune deficiency syndrome alkaline phosphatase alanine transaminase antineutrophil cytoplasmic antibodies adenomatous polyposis coli 5-aminosalicylic acid Anti-saccharomyces cerevesiae antibody aspartate transaminase adenosine triphosphate adenosine triphosphatase arteriovenous malformation bile acid transporter basal energy expenditure beta human chorionic gonadotrophin body mass index basal metabolic rate bovine spongiform encephalopathy ionized calcium cyclic adenosine 3′,5′-cyclic monophosphate charge-coupled device cholecystokinin Crohn’s disease capsule endoscopy carcinoembryonic antigen cystic fibrosis transmembrane regulator cyclic guanosine monophosphate calcitonin gene-related peptide chloride ion Campylobacter-like organism cytomegalovirus carbon dioxide coenzyme A colorectal cancer C-reactive protein computed tomography computed tomography colonography chemoreceptor trigger zone ionized copper dopamine divalent metal transporter deoxyribonucleic acid entero-chromaffin-like enterohaemorrhagic Escherichia coli enteropathogenic Escherichia coli endoscopic retrograde cholangiopancreatography erythrocyte sedimentation rate enterotoxigenic Escherichia coli endoscopic ultrasound familial adenomatous polyposis ferrous iron ferric iron faecal immunochemical test γ-amino butyric acid gastrointestinal stromal tumour γ-glutamyl transferase glyceryl trinitrate ionized hydrogen water histamine receptor type hydrochloric acid bicarbonate ion high-density lipoprotein 5-HIAA HIV HNPCC HPN 5HT IBAM IBD IBS IEL IF iFOBT Ig IL IMMC IPSID K+ LDH LDL MAD-CAM MEN Mg2+ MHC MOAT MRA MRCP MRE MRI NA Na+ NAPQI NH4+ NO NPY NSAIDs OAT PBC PET pIgA PLA2 POMC PYY PSC PT RNA SBP SC SGLT sIgA SOD STa TECK TGFβ TIPSS TNFα TPN tTG UC UDP USS VC VIP VLDL WHO 5-hydroxyindole acetic acid human immunodeficiency virus hereditary non-polyposis colon cancer home parenteral nutrition 5-hydroxytryptamine idiopathic bile acid malabsorption inflammatory bowel disease irritable bowel syndrome intra-epithelial lymphocyte intrinsic factor immunochemical faecal occult blood test immunoglobulin interleukin interdigestive migrating motor complex immunoproliferative small intestinal disease ionized potassium lactate dehydrogenase low-density lipoprotein mucosal addressin-cell adhesion molecule multiple endocrine neoplasia ionized magnesium major histocompatibility complex multispecific organic anion transporter magnetic resonance angiography magnetic resonance cholangiopancreatography magnetic resonance enteroclysis/enterography magnetic resonance imaging noradrenaline ionized sodium N-acetyl-p-benzoquinone-imine ammonium ion nitric oxide neuropeptide Y non-steroidal anti-inflammatory drugs organic acid transport primary biliary cirrhosis positron emission tomography polymeric immunoglobulin A phospholipase A2 pro-opiomelanocortin peptide YY primary sclerosing cholangitis prothrombin time ribonucleic acid spontaneous bacterial peritonitis secretory component sodium–glucose co-transporter secretory dimeric immunoglobulin A sphincter of Oddi dysfunction heat-stable enterotoxin thymus and epithelial expressed chemokine transforming growth factor β transjugular intrahepatic porto-systemic shunt tumour necrosis factor α total parenteral nutrition tissue transglutaminase ulcerative colitis uridine diphosphate ultrasound scanning vomiting centre vasoactive intestinal peptide very low-density lipoproteins World Health Organization List of abbreviations  Introduction and overview Endocrine system Central nervous system Mouth Blood vessels Oesophagus Peripheral nerves Liver Digestion, absorption, nutrition Stomach Gallbladder Hepatic portal vein Pancreas Colon Functional anatomy Small intestine Epithelium Enteric endocrine cells Immune cells Intrinsic nerves Extrinsic nerves Mucosa Muscularis mucosae Rectum Diseases and disorders Submucosa Muscularis propria Serosa Anus The Gastrointestinal System at a Glance, Second Edition Satish Keshav and Adam Bailey 8  © 2013 Blackwell Publishing Ltd Published 2013 by Blackwell Publishing Ltd 49 Functional tests H2 CO2 Lactulose Lactose Vitamin B12 13C-urea Oesophageal manometry pH monitoring, Bernstein test 24-hour pH monitor Reflux Reflux and pain and pain Xylose, rhamnose pH Urease breath test 13CO 13C urea H pylori Urease Urea Time NH4+ Schilling test Indicator dye colour CLO test pH↑ B12 deficiency I.M loading dose saturates body stores Lactulose Small intestinal bacterial fermentation Lactose Colonic bacterial fermentation H2 Oral test dose (labelled) Organic acids Normal excretion ↓Excretion = dietary deficiency = malabsorption H2 Oral test dose + IF Normal excretion = IF deficiency (pernicious anaemia) Organic acids B12 Anorectal manometry Xylose Kidney The Gastrointestinal System at a Glance, Second Edition Satish Keshav and Adam Bailey 106  © 2013 Blackwell Publishing Ltd Published 2013 by Blackwell Publishing Ltd ↓Excretion = terminal ileal disease Functional tests measure aspects of gastrointestinal pathophysiology and complement endoscopy, radiological imaging and blood tests There are many specific tests available, some of which are no longer in common usage, but they illustrate some of the important underlying principles discussed here Breath tests The principle underlying these tests is that gases such as CO2 and H2 that can be generated in the intestine are rapidly absorbed into the circulation and excreted through the lungs 13 C-urease breath test This test detects the presence of the urease enzyme of Helicobacter pylori in the stomach A drink containing 13C-labelled urea is administered and, after a short interval, a sample of expiratory breath is taken to detect the presence of 13C-labelled CO2, produced by the breakdown of 13C- urea, principally by the urease enzyme of H pylori 13C is a non-radioactive isotope and it is measured by mass spectrometry; similar tests use 14C-labelled urea, which emits beta particles that are detected by scintigraphy Lactose breath test A test meal containing lactose is administered, and the amount of H2 excreted on the breath is measured over the subsequent few hours Lactose is usually digested in the intestine by the enzyme lactase and absorbed, resulting in no excess production of H2 However, in lactase deficiency, either congenital or acquired, for example after a bout of gastroenteritis, lactose passes undigested into the large intestine, where bacteria metabolize it, releasing H2 The excess H2 is absorbed into the bloodstream and excreted via the lungs Lactulose breath test Lactulose is a disaccharide that is not absorbed or metabolized in the small intestine but passes to the colon, where bacteria digest it, releasing H2 H2 is produced after a delay necessitated by the passage of lactulose through the small intestine However, where there is bacterial overgrowth in the small intestine, lactulose metabolism occurs in the small intestine and is accelerated, resulting in excessive and early H2 production Absorption and excretion tests The principle underlying these tests is that tracer compounds absorbed from the intestine can be readily detected in the bloodstream or in the urine when they are excreted The chosen tracer compounds are easily detected, either by measuring radioactivity or by a simple chemical test Schilling test This test investigates the various steps in the absorption of vitamin B12 (hydroxocobalamin) It is rarely used nowadays due to lack of production of the cobalt radioisotopes and labeled-B12 test substances First, a large dose of vitamin B12 is administered by intramuscular injection, to saturate body stores and ensure that any additional vitamin B12 that is absorbed will be excreted in the urine rather than stored Next, an oral dose of radiolabelled vitamin B12 is administered and the urinary excretion measured Providing that intestinal absorption is normal, most of the labelled vitamin will be detected in the urine, suggesting that any previous deficiency was due to dietary insufficiency If, however, excretion cannot be detected, implying that there is inadequate intestinal absorption, a further oral dose of radiolabelled vitamin B12 is administered, this time together with intrinsic factor (IF) If exogenous IF restores normal absorption and excretion, the interpretation is that the patient has pernicious anaemia or IF deficiency caused by atrophic gastritis If, however, exogenous IF fails to restore normal absorption and excretion, the likely cause of the vitamin B12 deficiency is disease of, or damage to, the terminal ileum Xylose excretion Xylose is a non-metabolized sugar that is absorbed in the small intestine Once absorbed into the bloodstream, it is excreted unchanged in the urine Thus, urinary excretion allows intestinal absorption and permeability to be measured The xylose excretion test is mainly used as a research tool Stimulation tests In these tests, a hormone or other physiological stimulus is administered and the response noted In most cases, this involves measuring the secretion of another hormone or chemical into the circulation Secretin test This test is used to assess the extent of functional pancreatic tissue The duodenum is intubated and secretin infused intravenously The amount of pancreatic juice secreted and the HCO3− concentration and content are measured These are directly correlated with the amount of functional pancreatic tissue, and low levels indicate pancreatic insufficiency caused, for example, by chronic pancreatitis The test can be augmented by also infusing cholecystokinin and measuring pancreatic enzyme secretion Manometry Pressure transducers introduced into parts of the intestinal tract allow the function of sphincters to be studied The most commonly performed measurements are of the lower oesophageal and anal sphincters and the sphincter of Oddi Oesophageal manometry is used to diagnose various dysmotility disorders, including diffuse oesophageal spasm and achalasia of the cardia, while anal manometry helps in the diagnosis of the causes of faecal incontinence pH measurement pH electrodes introduced into the oesophagus and stomach through the nose or mouth allow the frequency and severity of gastro-oesophageal acid reflux to be evaluated Episodes of low pH in the distal oesophagus are correlated with symptoms, to ensure that reflux symptoms are actually caused by acid reflux The test can be used to document the effects of medical and surgical treatment In the Bernstein test, dilute HCl may be infused into the lower oesophagus to determine whether this reproduces heartburn for the patient This test is not commonly used Oesophageal pH measurement can be performed in ambulatory patients, over a 24-hour period, allowing documentation of the effects of meals, posture and sleeping Functional tests  Diagnosis and treatment  107 50 Pharmacotherapy Single effect/cell target, many receptors One substance (5HT), many receptor subtypes HCl output reduced Enteroendocrine cells Proton pump inhibitor 5HT4 receptor 5HT3 receptor Somatostatin lity eas Incr ed moti lit y H2 receptor antagonist Buccal or oral absorption, e.g GTN, Buccastem Anticholinergic ti eased Decr mo Endoscopic injection, e.g botulinum toxin Smooth muscle cell Hepatic first-pass metabolism Enteric neuron Gastric absorption, e.g alcohol, NSAIDs 5-ASA Probiotics (e.g Lactobacillus) Enteric coated A 5-AS Budesonide Enzyme and food Sulpha supplement s Non-absorbed antibiotics (e.g neomycin) Bacterial metabolism 5ASA active Intestine-specific chemokine, e.g CCL25 5ASA released Rectal absorption, e.g diazepam Intestinespecific adhesion receptor, e.g MAD-CAM Enema – local action or absorbed Suppository The Gastrointestinal System at a Glance, Second Edition Satish Keshav and Adam Bailey 108  © 2013 Blackwell Publishing Ltd Published 2013 by Blackwell Publishing Ltd Intestine-specific chemokine receptor, e.g CCR9 Intestine-specific adhesion receptor, e.g α4β7 integrin Pharmacological treatment of gastrointestinal disorders is a mature and well-advanced field, and new treatments are constantly emerging The biggest-selling drugs recently have been gastrointestinal acid suppressants, reflecting the high incidence of dyspepsia and peptic ulceration, and also the exquisite specificity of the medications, with a resulting low incidence of adverse effects Special considerations Target specificity Many drugs selectively bind to cellular receptors or proteins By mimicking the structure of the naturally occurring chemical, its effect is either replicated (agonist), or blocked (antagonist) One example is the histamine type (H2) receptor antagonists that block acid secretion by the parietal cells With advancing scientific knowledge, greater specificity can be achieved: for instance, different serotonin (5-hydroxytryptamine, 5HT) receptor subtypes are now being selectively targeted Immunological specificity Many intestinal diseases, such as Crohn’s disease and ulcerative colitis, have an immunological basis, and are treated by immunosuppression This typically involves the use of corticosteroids, thiopurines and anticytokine antibodies such as infliximab, which is directed against tumour necrosis factor (TNFα) A major disadvantage of such treatment is that it causes global immunosuppression and increases the risk of infection However, it is now possible to target the immune system specifically in only one organ system, because certain subtypes of lymphocytes, adhesion molecules, and chemokines and chemokine receptors are tissue-specific An approach currently being tested is to block the chemokine receptor CCR9, which is intestine-specific, in active Crohn’s disease This approach to treatment could allow effective treatment with much less risk of infection Selective release and topical treatment Another way of achieving selective effects is to apply the medication only where it can reach the target tissue In the gastrointestinal system, this can be achieved by oral administration of non-absorbed drugs that then act locally Mesalazine, or 5-aminosalicylic acid (5ASA), used to treat inflammatory bowel disease (IBD), is delivered in this way, either as a slow-release preparation that is active in the distal intestine, or as a pro-drug that is activated by bacterial enzymes in the colon Some drugs are significantly absorbed through the rectal mucosa, such as diazepam, used to treat epileptic seizures, while others, such as rectal 5ASA, act locally Other drugs are well absorbed through the oral and buccal mucosa, and can be administered this way without the need to be swallowed, which can be an advantage, for instance in treating vomiting (buccal preparations of the antiemetic prochlorperazine) Hepatic first-pass effect Enterically administered drugs that are rapidly and completely metabolized by the liver are said to have a high hepatic first-pass metabolism This allows high doses to be delivered to the intestine, with fewer systemic side-effects An example is the synthetic corticosteroid, budesonide, used to treat IBD Augmenting or inhibiting intestinal function Pancreatic enzyme supplements and lactase can be taken by mouth to correct the effects of pancreatic failure and intestinal hypolactasia, respectively The enzyme supplements act locally in the intestine Orlistat, which is designed to reduce fat absorption, acts by inhibiting pancreatic lipase in the intestine Oral tolerance, immunotherapy and vaccination Orally administered antigens stimulate a strong secretory immune response, with IgA and IgM antibodies, while the systemic immune response is inhibited Thus, the live polio vaccine, and vaccines against salmonellae and Vibrio cholerae are administered orally Orally administered autoantigens may induce selective immunological tolerance and could be used to treat autoimmune diseases such as multiple sclerosis, although the results of clinical trials have so far been discouraging Antibiotics and probiotics Some intestinal symptoms may be due to a proliferation of abnormal intestinal bacteria or a reduced number of normal commensals, and oral or rectal administration of live commensal bacteria is currently being investigated, particularly in the treatment of IBD This is a counterpart to the administration of antibiotics to selectively decontaminate the intestinal lumen, for example before abdominal surgery Certain antibiotics are not absorbed systemically when administered orally, and these can be used to treat intestinal infection without systemic toxicity Examples include rifaximin, which is newly available, and vancomycin, which is usually administered intravenously, and when given orally, treats Clostridium difficile infection Food as therapy Intolerance to various food elements occurs, for example, in coeliac disease, lactose intolerance and cows’ milk protein, peanut and other food allergies A totally bland, antigen-free diet comprising monomers or short oligomers of carbohydrate, fat and protein (elemental diet) is considered to be effective in treating Crohn’s disease, although the mechanism of action is unknown Enteral, as opposed to parenteral, feeding, even in severely ill patients, is critically important, as the food-free intestine atrophies, increasing the risk of bacterial translocation and systemic sepsis Parenteral nutrition Providing all necessary nutrients without eating is difficult, and was impossible prior to the discovery of lipid preparations that could be safely administered intravenously It is now possible to provide total parenteral nutrition (TPN) intravenously, for instance after major surgery, for the time before enteral feeding can be re-established Rarely, intestinal failure is permanent, for instance after a vascular catastrophe causing infarction of the intestine In these cases, patients can nowadays be offered TPN at home, administered via a permanently indwelling catheter in a major vein such as the subclavian (home parenteral nutrition, HPN) The lipid component of TPN remains dangerous, however, and after a few years of HPN, most patients have liver damage that can ultimately lead to cirrhosis and liver failure Permanent venous cannulae are also at risk of infection, and can cause thrombosis of veins Pharmacotherapy  Diagnosis and treatment  109 51 Gastrointestinal surgery Cholecystectomy Laparotomy Appendicectomy Cholecystectomy Nissen fundoplication Liver transplant Gastric bypass Instrument channel Emergency ulcer surgery Colectomy for bowel cancer Light source and air insufflator Hernia repair Appendicectomy Haemorrhoidectomy Ileostomy bag Incision and drainage of abscess The Gastrointestinal System at a Glance, Second Edition Satish Keshav and Adam Bailey 110  © 2013 Blackwell Publishing Ltd Published 2013 by Blackwell Publishing Ltd Incision of the abdominal wall to gain access to the peritoneal cavity is termed laparotomy Minimally invasive laparoscopic surgery has transformed many abdominal operations from major, hazardous undertakings to routine day-case procedures However, gastrointestinal surgery is frequently performed as an emergency and remains highly demanding for both patient and surgeon In addition, many gastrointestinal disorders are treated jointly by physicians and surgeons, who collaborate to determine the best combined therapeutic approach for individual patients, particularly when managing inflammatory bowel disease (IBD) and hepatobiliary conditions Basic considerations As for any surgery performed under general anaesthetic, patients fast beforehand, and for intestinal surgery, the bowel is also purged with laxatives, and prophylactic antibiotics are administered perioperatively Manipulating the intestine temporarily halts peristalsis, causing paralytic ileus; therefore, patients cannot eat or drink immediately after abdominal surgery Stomas Parts of the intestinal tract are commonly brought out onto the surface of the abdomen, creating an artificial opening or stoma This may be permanent or temporary, allowing time for the distal part of the bowel to heal, or to defunction the distal intestine prior to further surgery Stomas release intestinal or colonic contents onto the skin, which is not adapted for constant exposure to their pH, salt and enzymatic composition; therefore, stomas require special care, involving equipment such as adhesive dressings and bags In addition, small intestinal stomas lose large volumes of intestinal juice that can no longer be reabsorbed by the colon, and patients risk salt and water depletion unless they compensate by increasing their intake Laparoscopic surgery Operations such as a cholecystectomy are now usually performed laparoscopically, whereby, instead of a large incision of the anterior abdominal wall, a small ‘keyhole’ incision is made through which a narrow laparoscope is inserted This allows visualization of the internal organs, and instruments are introduced through the same or additional incisions to perform the surgery The technique requires skill and practice and is much less traumatic for the patient Common operations • Cholecystectomy:  usually to remove symptomatic gallstones causing cholangitis or pancreatitis • Hernia repair:  such as inguinal hernias, particularly in men • Appendicectomy:  usually for acute appendicitis Gastrointestinal bleeding Fifty per cent of gastrointestinal bleeding is caused by peptic ulcers, and although many cases can be treated medically, endoscopically or radiologically with arterial embolization, uncontrollable bleeding, especially where the bleeding source cannot be identified, necessitates emergency laparotomy Gastrointestinal bleeding caused by portal hypertension may require surgically constructed vascular shunts (portocaval shunts) to reduce portal pressure and prevent variceal haemorrhage Inflammatory bowel disease Inflammatory bowel disease, particularly Crohn’s disease, can cause intestinal strictures and fistulae that require surgical correction However, as Crohn’s disease typically recurs after surgery, surgery is used sparingly Medically uncontrolled colitis may necessitate emergency colectomy as a life-saving measure Furthermore, in ulcerative colitis, colectomy is curative and is sometimes also performed because of the high risk of colorectal cancer Cancer Cancers of the intestinal tract, pancreas, liver or gallbladder may be treated surgically, particularly if they are detected at an early, potentially curable stage However, most operations are palliative, aiming to reduce tumour bulk before chemotherapy or radiotherapy, or to relieve intestinal obstruction or bleeding Obesity Surgical treatment of obesity (bariatric surgery) is a rapidly growing area in which a variety of operations are performed The earliest operations, in which the jejunum and varying lengths of ileum were bypassed, achieved weight loss but were complicated by steatohepatitis causing severe liver damage, and are no longer performed Gastric bypass operations (roux-en-Y gastric bypass) are the most common bariatric surgical procedures performed However, smaller operations whereby a portion of the stomach is stitched or enclosed with a rubber band (laparoscopic adjustable gastric band), which can be adjusted to vary the effect, probably lead to less durable weight loss (see Chapter 38) Transplantation Transplant surgery may be performed to replace the liver, pancreas or pancreatic islet tissue, or small intestine Orthotopic liver transplantation, whereby the original liver is removed and replaced with a donor organ, is the most successful, and 85% of liver transplant recipients survive for at least years postoperatively Pancreatic and small intestinal transplantation are less successful, although when the small intestine and liver are transplanted together, the outcome improves, possibly because liver transplantation induces donor-specific immune tolerance in the host, reducing the risk of rejection Gastrointestinal surgery  Diagnosis and treatment  111 Index Page numbers in italics refer to figures abdomen examination 98, 99 abdominal pain 23, 31 coeliac disease 83 colon 35 epigastric 21, 72, 73, 74, 75 food poisoning 77 gallstones and pancreatitis 92, 93 syndromes 70, 71 abdominal surgery 69 abscesses anal 37, 90, 91 appendiceal 33 brain 79 Crohn’s disease 80, 81 liver 25, 33, 79 peri-anal 78, 79 tooth 11 absorption 48, 49 calcium 20, 21 fats 54, 55 folic acid 48, 49 iron 19, 20, 21, 48, 49, 52 reabsorption 35, 56, 57 tests 106, 107 see also malabsorption accessory duct 22, 23, 39 acetaldehyde 62, 63 acetyl coenzyme A 58, 59, 62, 63 acetylcholine (ACh) 18, 19, 41, 44, 45 HCl production 75 acetylcholine (ACh) receptor antagonists 64, 65 acetylcholinesterase inhibitors 67 achalasia 17, 41 acini 13, 22, 23, 24, 29 acquired immune deficiency syndrome (AIDS) 77, 79 acrodermatitis enteropathica 53 actin 40, 41, 48 acute-phase response 61 addressins 46, 47 adenocarcinoma 17, 72, 73 adenomatous polyposis coli (APC) gene 86, 87 adenosine 3´,5´-cyclic monophosphate (cAMP) 57, 67 adenosine triphosphate (ATP) 51 adenyl cyclase 67 adhesins 77, 109 albendazole 79 albumin 60, 61, 62, 63 liver disease 95, 97, 98, 99 alcohol 62, 63 cirrhosis 25, 96, 97 hepatitis 94, 95 malnutrition and 84, 85 pancreatitis 93 peptic ulcers 74, 75 alcohol dehydrogenase 62, 63 aldehyde dehydrogenase 62, 63 alkali tide 19 alkaline phosphatase 95, 98, 99 allergies 47  cells 22, 23 -fetoprotein (AFP) 88, 89 alveolar bone 10, 11 amino acids 50, 51, 55, 58, 59 essential and non-essential 60, 61 5-aminosalicylic acid 81, 91, 108, 109 ammonia 29, 61, 63 amoeboma 78, 79 amphetamines 84, 85 ampulla of Vater 20, 21, 22, 23, 27 endoscopy 103 amylase 22, 23, 49, 50, 51 -amylase 12, 13 levels 98, 99 anaemia 21, 35, 53 blood count 99 coeliac disease 83 colorectal cancer 86, 87 Crohn’s disease 80, 81 peptic ulcers 74, 75 worms 79 anaerobes 35 anaesthesia 15 anal canal 39 anal fissure 37, 68, 69, 90, 91 anal sphincter 36, 37, 69 anal valves 37 angiodysplasia 35 angular stomatitis 11 annular pancreas 39 anorectal angle 36, 37 anorectal canal 39 anorectal disease 90, 91 anorectal syndromes 70, 71 anorexia 45, 85, 93 hepatitis 95 antacids 74, 75 antibiotics 108, 109 bacterial overgrowth 78, 79 Crohn’s disease 81 diarrhoea 67, 77 H pylori infection 74, 75 intestinal infections 79 liver disease 78, 79 prophylactic 79 antibodies 81, 83 antimitochondrial 97 monoclonal 105 anticholinergic drugs 13, 69, 75 antidepressants 71 antidiarrhoeals 67, 71, 77 antiepileptics 63 antifungals 79 antigens 47 autoantigens 109 carcinoembryonic 87 antigliadin antibody test 83 antimitochondrial antibodies 97 antineutrophil cytoplasmic antibodies (ANCA) 81 antiretrovirals 95 antispasmodics 71 antrum 18, 19 The Gastrointestinal System at a Glance, Second Edition Satish Keshav and Adam Bailey 112  © 2013 Blackwell Publishing Ltd Published 2013 by Blackwell Publishing Ltd anus 36, 37 imperforate 38, 39 sensory nerves 45 anxiety 71 aphthous ulcers 11, 81 apolipoprotein B deficiency 51 apolipoproteins 50, 51, 58, 59, 60, 61 apoptosis 83 appendicectomy 33, 110, 111 appendicitis 32, 33, 45 appendix 32, 33 appetite control 42, 54, 55 appetite suppressants 84, 85 arachidonic acid 53 arthralgia 81 arthritis 81 ascites 28, 29, 96, 97 ultrasound scanning 105 aspiration 15, 17 vomit 65 aspirin 75, 87 asterixis 29 ATPase pump 19 atresia 39 atrophy gastrointestinal 85 subtotal villus 82, 83 auscultation 99 autoantigens 109 autocatalysis 51 autodigestion 49 autoimmune hepatitis 94, 95 autoimmune liver disease 96, 97 autoimmune pancreatitis 93 autonomic nerves 37, 44, 45, 49 autonomic neuropathy 19, 45, 66, 67 B cells 47 Bacillus cereus 76, 77 bacteraemia, systemic 77 bacteria bowel function 70, 71 colon 35 commensal 33, 46, 47, 48, 49, 78, 79, 109 food poisoning 76, 77 intestinal metabolism 28, 29 in the mouth 11 overgrowth 31, 78, 79, 107 pancreatitis 93 peritonitis 29, 79 toxins 57, 66, 67 translocation 29 see also specific bacteria balloon enteroscopy 101 barbiturates 63 bariatric endoscopy 103 bariatric surgery 111 barium contrast X-rays 75, 104, 105 barium meal 81, 104 barium swallow 73, 104 Barrett’s oesophagus 17, 72, 73, 88, 89 basal energy expenditure (BEE) 55 basal metabolic rate (BMR) 54, 55, 84, 85 behavioural therapy 71 Bernstein test 106, 107 -blockers 29  cells 22, 23 betel nut chewing 11 bicarbonate ions 23, 49, 56, 57 measurement 107 bile 20, 21, 27, 49 gallstones 92, 93 bile acid transporter (BAT) 26, 27 bile acids 21, 24, 25, 26, 27, 50, 51 amphiphilic 48, 49 diarrhoea 67 gastric reflux 73 ileum 30, 31 synthesis 59 bile canaliculi 24, 25, 26, 27 bile ducts 20, 23, 24, 26, 27 formation 38, 39 biliary cirrhosis, primary 27, 53, 96, 97 biliary epithelial cells 21, 25 biliary obstruction 63 biliary syndromes 70, 71 biliary system 9, 26, 27 bilirubin 24, 25, 26, 27, 62, 63 liver disease 95, 98, 99 biliverdin 62, 63 biopsies 101 duodenal 79 gastric ulcers 75 liver 97, 104, 105 mucosal 81, 83 biting 48, 49 bleeding gastrointestinal 111 haemorrhoids 91 peptic ulcers 102, 103 rectal 86, 87 bloating 51 blood–brain barrier 65 blood count 99 blood glucose levels 55, 59 blood pressure control 45 blood tests 55, 98, 99 body folding 39 body mass index (BMI) 54, 55, 84, 85 examination 98, 99 bone formation 53 botulinum toxin injections 41, 103 bovine spongiform encepalopathy (BSE) agent 47 bowel habit altered 35, 69, 98, 99 colorectal cancer 86, 87 see also constipation; diarrhoea brain abscess 79 appetite control 43 blood–brain barrier 65 and functional disorders 70 neurological damage 68, 69 salivary secretion 13 see also cortex; hypothalamus brainstem salivary nuclei 13 breath tests 79, 106, 107 Brunner’s glands 20, 21, 31 brush border 20, 21, 51 disaccharides 49 buccinator muscle 10, 11 buccopharyngeal membrane 38, 39 Budd–Chiari syndrome 94, 95, 105 budenoside 29, 81, 108, 109 bulb, duodenum 21 C-reactive protein (CRP) 61, 81, 93, 98, 99 C-urease breath test 106, 107 caecal volvulus 32, 33 caecum 32, 33 formation 38, 39 muscles 41 calbindin 52, 53 calcitonin gene-related peptide (CGRP) 44, 45 calcium 52, 53 absorption 20, 21 coeliac disease 83 contraction 40, 41 deficiency 55 fluid balance 56, 57 in pancreatitis 23 saliva 12, 13 calprotectin 99 Campylobacter 76, 77 Campylobacter-like organism (CLO) test 75 Candida albicans 78, 79 candidiasis 17, 79 canine teeth 10, 11 cannabinoids 65 carbo-loading 59 carbohydrates digestion 50, 51 energy density 55 liver function 58, 59 carbonic anhydrase 56, 57 carboxypeptidases 50, 51 carcinoembryonic antigen (CEA) 87 carcinogens, colorectal cancer 86, 87 carcinoid syndrome 42, 43, 88, 89 carcinoid tumours 33, 42, 43 carcinoids 67, 89 cardia 18, 19 carrier proteins 61 catecholamines 59 cellulose 51 cementum 10, 11 central nervous system 43 cephalic phase 19 cervical sympathetic chain 44, 45 chemokines 46, 47, 108, 109 chemoreceptor trigger zone (CTZ) 64, 65 chemotherapy, colorectal cancer 87 chewing see mastication chief cells 18, 19 cholangiocarcinoma 88, 89 cholangitis 27, 92, 93 hepatitis 94, 95 cholecystectomy 110, 111 cholecystitis 27, 92, 93 cholecystokinin 21, 23, 26, 27, 41, 42, 43 in nerve control 45 cholera 66, 67, 76, 77 cholera toxin 56, 57 cholera toxin A 67 cholesterol 21, 26, 27 stones 92, 93 synthesis 58, 59 cholesterol esterases 50, 51 13 cholesterol esters 49, 50, 51 chronic heart failure 29 churning 48, 49, 50 gastric churning 40, 41 chylomicrons 49, 50, 51 chyme 19, 20, 41, 49 chymotrypsinogen 50, 51 cimetidine 43, 75 ciprofloxacin 77 circulating enteric hormone levels 43 cirrhosis from hepatitis 95 liver 9, 25, 29, 96, 97 liver cancer 88, 89 primary biliary 27, 53, 96, 97 clinical assessment cloaca 38, 39 cloacal membrane 38, 39 Clostridium difficile 76, 77, 79 Clostridium perfringens 76 clotting tests 99 coagulation factors 60, 61 coagulopathy 53, 61, 97 coeliac artery 19, 21, 23, 39 coeliac disease 9, 21, 82, 83 digestion and 51 gastrointestinal adenomas 89 mucosal immune system 47 nutrition and 55 coeliac ganglion 22, 23, 44, 45 Coeliac Society 83 coeliac trunk 25 cold sores 11 colectomy 35 colitis 80, 81 ischaemic 35 pseudomembranous 77 see also ulcerative colitis collaterals 29 colon 34, 35 bleeding lesions 103 fluid flux 56, 57 formation 39 mass movement 40, 41 megacolon 45, 69, 105 muscles 41 primitive 38, 39 sigmoid 34, 35, 36, 37 transit time 105 colonocytes 32, 33, 35 colonoscopy 81, 100, 101 colorectal cancer 87 colorectal cancer 9, 33, 35, 86, 87 screening 87, 101 ulcerative colitis 81 coma 15, 29 common bile duct 20, 23, 26, 27 complement proteins 61 computed tomography colonography (CTC) 87, 105 computed tomography (CT) scanning 105 computed tomography enterocyclis (CTE) 105 confocal endomicroscopy 101 conjugation 62, 63 constipation 37, 68, 69 carcinogens and 87 intestinal motility 70, 71 nerve dysfunction 45 slow-transit 41, 69 Index  113 constructional apraxia 29, 97 contractions 41 coordination, neuromuscular 49 copper 53 excretion 27, 63 corpus 18, 19 cortex 46, 47, 64, 65 constipation control 68, 69 corticosteroids 59, 81, 95, 109 cough 72, 73 Crigler–Najjar syndrome 63 Crohn’s disease 31, 33, 35, 80, 81 anorectal 37, 79, 80, 81, 91 colitis 80, 81 nutrition and 55 proctitis 91 surgery 111 terminal ileal 80, 81 vitamin deficiency and 53 crown 10, 11 Cryptosporidia 31, 76, 77 crypts abscesses 80, 81 caecum 33 colonic 35 jejunal and ileal 30, 31 of Lieberkühn 21 cyclic guanosine monophosphate (cGMP) 56, 57 cystic duct 25, 26, 27, 38, 39 cystic fibrosis 23 cystic fibrosis transmembrane regulator (CFTR) gene 93 cystic fibrosis transmembrane regulator (CFTR) protein 22, 23, 56, 57, 67 cysticercosis 79 cytochrome P450 62, 63 cytochromes 62, 63 cytokines 60, 61, 83 cytomegalovirus 76, 77, 78, 79 cytoskeletal proteins 27 D cells 19, 22, 23, 42, 43 defecation 36, 37, 41 frequency 67, 69 haemorrhoids 91 neuro-psychological dysfunction 69 see also faeces defensins 47 dehydration 57, 77 examination 99 dendritic cells 25, 46, 47 dental caries 11 dental hygiene 11 dentate line 36, 37 dentine 10, 11 depression 71 dermatitis 53 dermatitis herpetiformis 83 detoxification 62, 63 diabetes mellitus 23 autonomic neuropathy 19 blood glucose levels 59 candidiasis 17, 79 nerve damage 45 obesity 85 pancreatitis 92, 93 114  Index diarrhoea 51, 66, 67 anorectal disorders 37 antibiotics 67, 77 antidiarrhoeals 67, 71, 77 coeliac disease 83 colitis 81 duodenal disorders 21 endemic and epidemic 77 food poisoning 76, 77 intestinal motility 70, 71 osmotic 66, 67 pancreatic disorders 23 secretory 57, 66, 67 small intestine disorders 31 traveller’s 77 worms 78, 79 diazepam 108, 109 diet bowel function 71 colorectal cancer 86, 87 gastric cancer 89 gluten-free 83 low-calorie 84, 85 see also food; nutrition dietary fibre 51, 68, 69, 71, 87 digestion 48, 49 carbohydrates, proteins and fats 50, 51 vitamin B12 30, 31 vitamins and minerals 52, 53 digestive enzymes 9, 23 digital rectal examination 37, 69, 98, 99 dilatation 103 diphtheria 15 disaccharides 49, 50, 51 disulfiram 63 divalent metal transporter (DMT) 52, 53 diverticulae 34, 35 diverticulitis 34, 35 dome epithelium 46, 47 dopamine 44, 45 dopamine D2 receptor antagonists 64, 65 drugs anticholinergic 13, 69, 75 antidiarrhoeals 67, 71, 77 buccal 108, 109 constipation 69 hepatitis 94, 95 obesity 85 pharmacotherapy 108, 109 pro-drugs 109 slow-release 109 sublingual administration 11 suppositories 37 vomiting 64, 65 see also antibiotics; non-steroidal antiinflammatory drugs (NSAIDs) dry mouth 13, 15 Dubin–Johnson syndrome 63 Dukes staging 86, 87 duodenal cancer 21 duodenum 20, 21, 23 biopsies 79 digestion 49 formation 38, 39 gastroduodenal disorders 70, 71 ulcers 21, 74, 75 dysentery 35, 66, 67, 79 inflammatory response 77 dysmotility 17, 40, 41, 67, 79 dyspepsia 19, 73 non-ulcer 70, 71 dysphagia 17, 41, 89, 99 dysplasia 73 angiodysplasia 35 Echinococcus 79 ectoderm 39 electrochemical gradient 56 electrogastrography 41 electrolytes abnormalities 69 balance 56, 57 levels 98, 99 embryology 38, 39 emulsification 27, 48, 49, 50, 51 enamel 10, 11 demineralization 13 encephalopathy 29 Wernicke’s 85 see also hepatic encephalopathy endoanal ultrasound 105 endocarditis 79 endocrine action 43 endocrine dysfunction 85 endocrine pancreatic insufficiency 23 endocrine system 42, 43 endocrine tissue 23 endoderm 39 endopeptidases 50, 51 endoplasmic reticulum 22, 23 liver 24, 25 smooth 62, 63 endoscopic retrograde cholangiopancreatography (ERCP) 93, 102, 103, 104 endoscopy Barrett’s oesophagus 89 capsule 100, 101 diagnostic 100, 101 mucosal resection 73, 103 therapeutic 102, 103 ultrasound 101, 103 upper gastrointestinal 73, 75, 83, 100, 101 endothelial cells, liver 25 enema 37 energy density 55 energy expenditure 55 energy metabolism 53 Entamoeba histolytica 76, 77, 78, 79 enteral nutrition 55, 109 enteric hormones 42, 43 enteric motility 40, 41 enteric nerves 21, 44, 45, 49 entero–endocrine cells 18, 19, 20, 21, 42, 43 5HT release 41 entero–hepatic circulation 26, 27, 31 Enterobius vermicularis 91 enterochromaffin-like (ECLs) cells 18, 19, 42, 43 Enterococcus 79 enterocytes 20, 21 digestion 49, 51 enteroglucagon 42 enterokinase 21, 49, 51 enteroscopy 101 enterotoxins, heat-stable 56, 57 enzymes antibacterial 13 conjugation 62, 63 in digestion 49 digestive 9, 23 gastric reflux 73 oxidases 62, 63 pro-enzymes 23, 49 regulation 62, 63 see also pancreatic enzymes eosinophilic oesophagitis 17 eosinophils 46, 47 epigastric pain 21, 72, 73, 74, 75 epiglottis 14, 15, 16, 17 epinephrine 103 Epstein–Barr virus 15, 94 erythema nodosum 81 erythrocyte sedimentation rate (ESR) 99 erythromycin 41 Escherichia coli 35, 56, 57, 78, 79 enterohaemorrhagic (EHEC) 77 enterotoxigenic 76, 77 Escherichia histolytica 77 Eustachian tubes 15 excretion 62, 63 tests 106, 107 exercise 84, 85 exocrine glands 13, 22, 23 exopeptidases 50, 51 exterotoxins 76–7 facial nerve 12, 13, 15, 44, 45 faecal immunochemical test (FIT) 87 faecal occult blood 35, 99 testing 87 faecalith 32, 33 faeces expulsion 37 faecal–oral route 95 impaction 69 see also defecation falciform ligament 25, 39 familial adenomatous polyposis (FAP) 87 familial polyposis syndromes 21 fasting 69 fat-soluble vitamins 52, 53 fatigue 59 fats 85 absorption 54, 55 digestion 50, 51 droplets 25 energy density 55 storage 35 see also lipids fatty acids 21, 48, 49, 50, 55 liver function 58, 59 polyunsaturated 53 fauces 10, 11 fenestrae 24, 25 fever 76, 77, 81 fibrosis 25, 43 cystic 23 first-pass metabolism 29 fistula anal 37, 90, 91 oesophageal 17 tracheo–oesophageal 38, 39 flapping tremor 97 flatulence 31, 35 fluconazole 79 fluid balance 56, 57 fluid intake, inadequate 68, 69 fluoride 11 flushing 42, 43 folic acid 30, 31, 52, 53 absorption 48, 49 food allergies 47, 109 digestion and absorption 48, 49 poisoning 67, 76, 77 sweeteners 67 as therapy 109 vitamins in 53 see also diet; nutrition foregut formation 38, 39 frenulum 15 fronds 27 fructose 50, 51 functional disorders 45, 70, 71 fundoplication 73 fundus 18, 19 G cells 18, 19, 42 tumours 43 G-protein coupled receptors 15 gadolinium 105 galactose 50, 51 gallbladder 24, 25, 26, 27 formation 38, 39 ultrasound scanning 104, 105 gallstones 27, 92, 93 -glutamyl transferase (GT) 95, 98, 99 gap junctions 40, 41 Gardia lamblia 21, 31 gastrectomy, partial 74, 75 gastric antrum 75 gastric bypass surgery 84, 85, 110, 111 gastric cancer 74, 75, 88, 89 gastric churning 40, 41 gastric corpus 75 gastric glands 18, 19 gastric lymphoma 74, 75 gastric outlet obstruction 19 gastric phase 19 gastric pits 18, 19 gastric secretion 18, 19 gastric slow wave 19 gastric ulcers 74, 75, 89 gastrin 18, 19, 42, 43, 75 gastrinomas 23, 43 gastritis 19 atrophic 53, 55 gastric cancer 89 H pylori 74, 75 gastro-oesophageal reflux 72, 73, 89 gastrocolic reflex 41 gastroduodenal disorders 70, 71 gastroenteritis 51, 67, 76, 77 malnutrition and 85 gastroferrin 19, 52, 53 gastrograffin 105 gastrointestinal haemorrhage 29 gastrointestinal lymphoma 88, 89 gastrointestinal stromal tumours (GISTs) 89 gastrointestinal system infections 78, 79 gastroschisis 39 gel 35 genetic predisposition 98, 99 coeliac disease 83 colorectal cancer 86, 87, 101 selective lactase deficiency 51 ulcerative colitis and Crohn’s disease 80, 81 genitalia examination 99 ghrelin 42, 43, 54, 55 Giardia lamblia 76, 77 Gilbert’s syndrome 63 gingivae 10, 11 gliadin peptides 82, 83 globus hystericus 70, 71 glossitis 15 glossopharyngeal nerve 12, 13, 14, 15, 44, 45 glottis 14, 15 glucagon 22, 23, 42, 43 liver function 59 glucagonomas 43 gluconeogenesis 54, 55, 58, 59, 60, 61 glucose 50, 51, 54, 55 liver function 58, 59 production 60, 61 glucuronide 62, 63 glucuronyl transferase 62, 63 glutamine 82, 83 gluten enteropathy 83 glyceryl trinitrate 11, 91 glycogen 50, 58, 59 granules 24, 25 glycogenolysis 54, 55, 58, 59 glycolysis 58, 59 glycoproteins 20, 49 glycosaminoglycans 34, 35 goblet cells 19, 20, 21, 46 Barrett’s oesophagus 73 colonic 34, 35 depletion 81 Golgi apparatus 22, 23 granulomas 80, 81 greater omentum 34, 35, 39 growth charts 55 growth hormone 59 guanyl cyclase 56, 57 guanylin 56, 57 guarding 45 Guillain–Barré syndrome 77 gum infections 11 gut-brain peptides 43 H2 receptors 18, 19 haem 62, 63 haematemesis 17, 19, 21, 29, 65 peptic ulcers 74, 75 haematochesia 29, 35, 37 haemochromatosis 49, 53, 96, 97 haemoglobin 63 haemolysis 27, 62 haemolytic disorders 63 haemolytic–uraemic syndrome 77 haemorrhoidal plexus 37 haemorrhoids 36, 37, 90, 91 degrees 90, 91 prolapsed 68, 69 treatment 101 haustra 34, 35 HCO3– see bicarbonate ions HCO3–/Cl- exchanger 56, 57 Index  115 heart disease 84, 85 chronic heart failure 29 heart rate control 45 heartburn 17, 71, 72, 73 heat-stable enterotoxin (STa) 56, 57 Helicobacter pylori 9, 19, 47, 73, 74, 75, 89 detection 106, 107 helminthicides 79 hepatic artery 24, 25 hepatic encephalopathy 28, 29, 63, 79, 96, 97 hepatic first-pass metabolism 108, 109 hepatic flexure 35 hepatic portal system 16, 17, 28, 29 hepatic portal vein 19, 22, 23, 30, 35 hepatic sinusoids 29 hepatic vein 24, 25, 28, 29 hepatitis 94, 95 viral 25, 27, 94, 95 hepatitis A 95 hepatitis B 89, 95 hepatitis C 95 hepatitis D 95 hepatitis E 95 hepatitis G 95 hepatocytes 24, 25, 27 cirrhosis 96, 97 5HT metabolism 42 vitamin storage 53 hepcidin 52, 53, 60, 61 hereditary non-polyposis colon cancer (HNPCC) 86, 87 hernial sacs 31 hernias hiatus 17, 19, 72, 73 repair 111 herniation 39 herpes simplex 11, 15, 78, 79 HFE protein 52, 53 hiatus hernia 17, 19, 72, 73 high-density lipoproteins (HDL) 59 hilum 24, 25, 29 hindgut formation 38, 39 Hirschsprung’s syndrome 45, 68, 69 histamine 18, 19, 42, 43 HCl production 75 histamine receptor (H1R) antagonists 64, 65 histamine receptor (H2R) antagonists 43, 73, 74, 75, 108, 109 hoarseness 72, 73 homeostasis 25 hookworms 31, 78, 79 hormones 42, 49 enteric 42, 43 liver metabolism 59 see also steroids 5HT (5-hydroxytryptamine) see serotonin 5HT (5-hydroxytryptamine) receptor antagonists see serotonin (5HT) receptor antagonists 5HT (5-hydroxytryptamine) receptors see serotonin (5HT) receptors human papillomavirus 91 hydatid disease 78, 79 hydrochloric acid (HCl) 18, 19, 49, 72, 73, 74, 75 5-hydroxyindole acetic acid 89 5-hydroxyindole acetic acid (5-HIAA) 43 hyoscine 41, 64 hyperammonaemia 63 hyperbilirubinaemia 63 116  Index hypercholesterolaemia 59 hypersensitivity 47 hypersplenism 29 hypertension 84, 85 hypertrophy, pyloric sphincter 40, 41 hypoalbuminaemia 61 hypocalcaemia 41, 68, 69, 93 hypoglossal nerve 14, 15 hypoglycaemia 59 hypokalaemia 41, 43, 65 paralytic ileus 68, 69 hyponatraemia 65 hypopharynx 15 hypothalamic centres 57 hypothalamus 44, 45, 64, 65 hypothyroidism 85 hypoxia 92, 93 idiopathic bile acid malabsorption (IBAM) 67 ileal brake 41 ileal disease 92, 93 ileocaecal tuberculosis 31 ileocaecal valve 30, 31, 32, 33 ileoscopy 101 ileum 30, 31 absorption 49 paralytic 41, 68, 69 paralytic ileus 41, 68, 69, 111 iliac fossa 45 immune system mucosal 46, 47 regulation 33 immune tolerance, donor-specific 111 immunity, zinc role in 53 immunochemical faecal occult blood test (iFOBT) 87 immunocompromised patients 17, 77, 79 immunoglobulin A (IgA) antibody 83 secretory dimeric 21, 46, 47 immunoglobulins 13 immunoproliferative small intestinal disease (IPSID) 31, 89 immunosuppression 81, 109 immunotherapy 109 imperforate anus 38, 39 incisors 10, 11 incontinence 37 causes of 36 overflow 69 indigestion 19 infections gum 11 H pylori 74, 75 intestinal 78, 79 inferior mesenteric artery 34, 35, 39 inferior mesenteric vein 22, 28, 29, 34, 35, 39 inferior vena cava 24, 25 inflammation 37, 60, 61 chronic intestinal 87 diarrhoea 66, 67 dysentery 77 inflammatory bowel disease 9, 35, 47, 79 diarrhoea 66, 67 see also Crohn’s disease; ulcerative colitis inflammatory mass 81 influenza 15 prodromal 95 insulin 22, 23, 29 liver function 59 secretion 42, 43 integrated function interdigestive migrating motor complex (IMMC) 40, 41 interferon 82, 83 interferon  95 interleukin (IL-6) 61 intestinal failure 31 intestinal housekeeper 41 intestinal membrane calcium-binding protein 52, 53 intestinal motility 70, 71 intestinal tract intestinal tuberculosis 31 intoxication 15 intra-abdominal pressure 36, 37, 72, 73 intra-epithelial lymphocytes 46, 47 intrahepatic cholestasis 27, 63 intravenous rehydration 67, 77 intrinsic factor 18, 19, 48, 49, 52, 53 Schilling test 107 intrinsic nerves 37 iritis 81 iron absorption 19, 20, 21, 48, 49, 52 coeliac disease 83 deficiency 11, 53 irritable bowel syndrome (IBS) 35, 70, 71 diagnostic criteria 71 dysmotility 41 nerve function disorder 45 post-infectious 77 ischaemic colitis 35 isoniazid 95 itching 27, 37, 91 anal 71 Ito cells 53 Janus kinase (JAK2) 95 jaundice 23, 25, 27, 63, 89 cirrhosis 96, 97 hepatitis 94, 95 jejuno-ileal bypass 84, 85 jejunum 30, 31 digestion 49 ketones 55, 58, 59 KRAS gene 86, 87 Krebs cycle 58, 59, 60 Kupffer cells 24, 25, 29 kwashiorkor 84, 85 lactase 50, 51, 109 deficiency 51, 66, 67, 107 lactate 58, 59 lactate dehydrogenase (LDH) 58, 59 lacteals 51 lactic acidosis 59 Lactobacillus 78, 79 lactose 50, 51, 67 breath test 106, 107 intolerance 77 lactulose 63, 67 breath test 106, 107 lamina propria 21, 35, 81, 83 lymphocytes 46, 47 laparoscopic adjustable gastric band 84, 85, 111 laparoscopic surgery 111 laparotomy 110, 111 larynx 15, 16, 17 laxatives 67, 68, 69, 71 leptin 42, 43, 54, 55, 84, 85 lesser omentum 39 levator ani muscle 36, 37 lifestyle changes 71, 73 history 98, 99 ligament of Treitz 21 linoleic acid 53 linolenic acid 53 lipases 22, 23, 49 levels 99 lipids 50, 51 antigens 47 liver function 58, 59 see also fats lipoproteins 58, 59 see also apolipoproteins liposuction 84, 85 lips 10, 11 liver 9, 19, 24, 25, 26 abscesses 25, 33, 79 biopsies 97, 104, 105 cell damage 94, 95 detoxification and excretion 62, 63 fatty 95 formation 38, 39 hepatic portal system 28, 29 metabolic function 58, 59 protein synthesis 60, 61 synthetic function 60, 61 transplantation 95, 97, 110, 111 liver bud 38, 39 liver cancer 25, 88, 89 liver disease acute 9, 94, 95 antibiotics 78, 79 chronic 9, 55, 96, 97 see also cirrhosis liver disorders 25 liver failure 25, 94, 95 fulminant 63 synthetic 61 loperamide 77 lymphadenopathy 99 lymphocytes 25, 46, 47, 82, 83 lymphoid tissue 33 lymphoma gastric 74, 75 intestinal 47, 83, 88, 89 lysosomes 24, 25 lysozyme 12, 13, 47 M2 muscarinic receptors 19 macronutrients 51, 55 macrophages 46, 47 magnetic resonance angiography (MRA) 105 magnetic resonance cholangiopancreatography (MRCP) 103, 105 magnetic resonance enterocyclis (MRE) 104, 105 magnetic resonance imaging (MRI) 104, 105 major histocompatability complex (MHC) class II genes 83 malabsorption 21, 23, 31, 49, 51 bacterial overgrowth 79 coeliac disease 83 diarrhoea 66, 67 and nutrition 55 pancreatitis 93 Mallory–Weiss tear 17, 65 malnutrition 49, 84, 85 MALT lymphoma 89 maltase 50, 51 maltose 50, 51 maltotriose 50, 51 mandible 10, 11 manometry 106, 107 oesophageal 73 marasmus 85 masseter muscle 10, 11 mast cells 46, 47 mastication 11, 13, 48, 49 muscles 10 maxilla 10, 11, 12 maxillary sinus 11 mebeverine 41 Meckel’s diverticulum 30, 31, 38, 39 medulla oblongata 65 megacolon 45, 69, 105 melaena 19, 21, 29 peptic ulcers 74, 75 memory disturbance 29 menstruation cessation 85 mesalazine 81, 109 mesentery 30, 31, 33, 38, 39 mesoderm 39 metabolic acidosis 65 metabolic adaptation 84, 85 metabolic alkalosis 65 metabolic failure 59 metaplasia 17 metastasis colorectal cancer 86, 87 liver cancer 25, 88, 89 metoclopramide 41, 64, 65 metronidazole 15, 77 micelles formation 48, 49 mixed 27, 50, 51 microfold (M) cells 46, 47 micronutrients 51, 52, 55 excretion 63 microsomal oxidases 63, 95 Microsporidia 31, 76, 77 microvilli 20, 21, 24, 25, 48, 49 mid-arm circumference 54, 55 mid-gut formation 38, 39 milk teeth 10, 11 minerals deficiencies 55 digestion 52, 53 mismatch repair genes 87 misoprostol 57, 75 mitochondria 24 liver 25 mixed micelles 27, 50, 51 molars 10, 11 monoclonal antibodies 105 monosaccharides 50, 51 motilin 42 motor nerves 44, 45 motor neurone disease 15 mouth 10, 11 sensory nerves 45 see also salivary glands; tongue mucins 46, 47 mucosal addressin-cell adhesion molecule (MAD-CAM) 46, 47 mucosal homing 47 mucosal immune system 46, 47 mucus 12, 13, 35 multiorgan/ multisystem failure 51, 92, 93 multiple endocrine neoplasia (MEN) 43, 89 multiple organ failure 85 multiple sclerosis 69 multispecific organic anion transporter (MOAT) 26, 27 mumps 13 muscular spasm 41 muscularis mucosae 20, 21, 41 myasthenia gravis 15 Mycobacterium tuberculosis 79 myenteric nerves 45 myenteric plexus 16, 17, 44, 45 myoglobin 62, 63 myosin 40, 41 N-acetyl-p-benzoquinone-imine (NAPQI) 63, 95 N-acetylcysteine 63, 95 Na+/K+ ATPase pump 19, 50, 51, 56, 57 nasopharynx 14, 15 nausea 64, 65, 93 neoplasia 31 neoplasms 83 neostigmine 41 neuroendocrine cells see entero–endocrine cells neuroendocrine tumours 23, 31, 88, 89 neuroglycopenia 59 neurological damage 63 coeliac disease 82, 83 neuropeptide Y 44, 45 neuropeptides 54 neurotransmitters 44, 45, 54, 55 vomiting 64, 65 neutropenia 79 neutrophils 46, 47 night-blindness 53 nitric oxide 41, 44, 45 nitrogen balance 55 NOD2 gene 31, 80, 81 non-steroidal anti-inflammatory drugs (NSAIDs) 19, 57, 74, 75, 86, 87 noradrenaline 44, 45 norfloxacin 79 Norwalk agent 76, 77 nucleases 49 nucleus of the tractus solitarius 13, 15 nutcracker oesophagus 41 nutrient storage 25 nutrition 54, 55 parenteral 55, 85, 109 see also diet; food nutritional deficiency biliary system 27 duodenum 21 malnutrition 49, 84, 85 Index  117 nutritional deficiency (cont’d ) mouth disorders 11 overnutrition pancreas 23 small intestine disorders 31 undernutrition nystatin 79 obesity 9, 84, 85 surgery 111 obstruction biliary obstruction 63 gallstones 27, 92, 93 gastric outlet 19 intestinal 74, 75 luminal 103 small intestine 31 octreotide 43 scan 89, 104 odynophagia 17, 89 oedema 61 peripheral 85 oesophageal adenocarcinoma 89 oesophageal cancer 17, 88, 89 oesophageal sphincter lower 16, 17 reflux 72, 73 upper 14, 15 vomiting 64, 65 oesophageal varices 17, 28, 103 oesophagectomy 73, 89 oesophagitis 17, 72, 73 oesophagoscopy 100, 101 oesophagus 16, 17 Barrett’s oesophagus 17, 72, 73, 88, 89 disorders 70, 71 dysmotility 40, 41 formation 39 muscles 16, 17 reflux 72, 73 venous drainage 28, 29 oligosaccharides 51 omental bursa 39 omeprazole 19, 73, 75 omphalocoele 38, 39 ondansetron 64, 65 opiates 41, 67 opioids 57 opportunistic disease 77 oral epithelium 49 oral hygiene 11 oral rehydration solution 51, 67, 77 oral tolerance 29, 47 orbicularis ori muscle 10, 11 organic acid transport (OAT) protein 26, 27 organic acids 11 orlistat 84, 85 oropharynx 15 osmotic gradients 56, 57 osmotic laxatives 68, 69 osteomalacia 53 osteomyelitis 79 osteoporosis 55, 83 overflow incontinence 69 oxidases 62, 63 microsomal 63, 95 oxyntic cells 19 118  Index pacemaker cells 40, 41 pain anorectal 37 defecation 69 dysmotility 41 haemorrhoids 91 history 98, 99 perception 71 peri-umbilical 33, 45 proctalgia fugax 71 referred 45 sensation 45 visceral 45 see also abdominal pain palpation 99 pancreas 9, 19, 20, 21, 22, 23, 26 digestion 48, 49 division 39 divisum 23 formation 38, 39 transplantation 111 pancreatic adenocarcinoma 23 pancreatic buds 38, 39 pancreatic duct 20, 22, 23, 26, 27, 39 pancreatic enzymes 48, 49, 92, 93 supplements 67, 109 pancreatic insufficiency 107 pancreatic islets 22, 23 pancreatic juices 20, 21, 49 pancreatic rest 39 pancreatic secretion 23 pancreatic tumours 88, 89 pancreatitis 27, 45, 51, 92, 93 acute 23, 92, 93 chronic 23, 92, 93 peptic ulcers 74, 75 Paneth cells 20, 21, 35, 46, 47 increase 80, 81 panproctocolectomy 81, 87 papillae, tongue 14, 15 paracetamol 63, 94, 95 paracrine action 42, 43 paralytic ileus 41, 68, 69, 111 parasympathetic nerves 36, 37, 44, 45 parenchyma 25 parenteral nutrition 55, 85, 109 parietal cells 18, 19, 53, 75 parotid glands 12, 13 pathogens 35 pepsin 19, 49, 50, 51 pepsinogen 19, 49, 50 peptic ulcers 19, 21, 74, 75 bleeding 102, 103, 111 peptidases 49, 50, 51 peptides 42, 43, 45, 50 percussion 99 perforation, caecum 33 peri-anal mass 90, 91 peri-umbilical pain 33, 45 perineal body 39 periodontal membrane 10, 11 peripheral neuropathy 68, 69 peristalsis 16, 17, 19, 40, 41, 49 anal 37 motor control 45 reverse 64, 65 peritoneum 23, 25 peritonitis 32, 33 bacterial 29, 79 peptic ulcers 75 permanent teeth 10, 11 peroxisomes 25 Peyer’s patches 30, 31, 46, 47 pH measurement 106, 107 pharyngeal muscles 14, 15 pharyngitis 15 pharynx 14, 15, 17 phasic contractions 41 phosphate, saliva 12, 13 phospholipases 51 phospholipids 26, 27, 48, 49, 50, 51 pigment stones 92, 93 plaque 10, 11 plasma proteins 60, 61 plastic brushes 101 plicae circulares 20, 21, 30, 31, 48, 49 pneumonia 15, 17, 65 polio vaccine 109 polypectomy 87, 102, 103 polypeptides 42 polyps, dysplastic 86, 87 polysaccharides 51 polyunsaturated fatty acids 53 portal hypertension 17, 28, 29, 96, 97, 105, 111 portal triads 24, 25, 29 portal vein 24, 25, 28, 29, 31, 33, 39 porto-systemic shunting 28, 29, 96, 97 transjugular intrahepatic 28, 29, 104, 105 positron emission tomography (PET) 105 pouch of Douglas 37 premolars 10, 11 primary biliary cirrhosis (BPC) 27, 53, 96, 97 primary sclerosing cholangitis (PSC) 80, 81, 89 prions 46, 47 pro-elastase 51 pro-enzymes 23, 49 probiotics 78, 79, 81, 108, 109 proctalgia fugax 37, 70, 71, 91 proctitis 37, 91 proctoscopy 37, 91, 101 prostaglandins 57, 74, 75 prostate gland 37 proteases 22, 51 inhibitors 61 proteinases 49 proteins carrier proteins 61 deficiency 84, 85 digestion 50, 51 energy density 55 plasma 60, 61 synthesis 60, 61 prothrombin time (PT) 61, 95 proton pump 18, 19 inhibitors 73, 74, 75 pruritis ani 71, 91 pseudomembranous colitis 77 pterygoids muscle 10, 11 puborectalis muscle 36, 37 pulp 11 pyloric sphincter 19 hypertrophy 40, 41 pylorus 19, 20, 21 pyoderma gangrenosum 81 pyruvate 58, 59 radiation proctitis 91 radioisotope scans 105 radiology, interventional 104, 105 radiotherapy, colorectal cancer 87 ranitidine 19, 43, 73, 75 reabsorption 56, 57 water 35 receptors 43 rectal bleeding 86, 87 rectal cancer 37 rectal columns 36, 37 rectal varices 28 rectum 35, 36, 37 anorectal syndromes 70, 71 formation 38, 39 venous drainage 28, 29 refeeding syndrome 84, 85 referred pain 45 reflex motility 41 reflux acid 17, 72 chronic 72, 73 rehydration intravenous 67, 77 oral rehydration solution 51, 67, 77 Reiter’s syndrome 77 retching 65 retinoic acid see vitamin A rheumatic fever 15 ribavirin 95 rice-water stool 67 rickets 53 rifampicin 79 rifaximin 77, 109 risk factors peptic ulcers 75 squamous carcinoma 11 rolling hiatus hernia 72, 73 rotavirus 76, 77 Rotor syndrome 63 roughage 51 roundworms 31, 78, 79 roux-en-Y gastrectomy 84, 85, 111 Saccharomyces cerevisiae 81 sacral motor neurons 36, 37 sacral parasympathetic plexus 45 saliva 12, 13, 48, 49 salivary glands 12, 13 Salmonella 76, 77, 78, 79 Salmonella typhi 31, 77 sarcoidosis 13 Schilling test 53, 106, 107 screening, colorectal cancer 87, 101 scurvy 53 secretin 21, 23, 42, 43 test 107 secretory cells 13 secretory dimeric immunoglobulin A (sIgA) 21, 46, 47 secretory granules 43 segmenting movement 40, 41 sensory nerves 44, 45 sentinel pile 90, 91 septum transversum 39 serological tests 75, 83, 98, 99 serotonin (5HT) 41, 42, 43, 57, 71 serotonin (5HT) receptor antagonists 64, 65, 68, 69, 71 serotonin (5HT) receptors 44, 45, 56, 57, 108, 109 serum amyloid A 61 sexually transmitted diseases 37, 91, 95 shape test 105 Shigella 47, 76, 77 short-bowel syndrome 31 shunts portocaval 111 surgical 28, 29 see also porto-systemic shunting sibutramine 84, 85 sigmoid colon 34, 35, 36, 37 sigmoidoscopy 37, 81, 101 sinusoids 25 Sjögren’s syndrome 13 skin-fold thickness 54, 55, 85 skip lesions 80, 81 sliding hiatus hernia 72, 73 slow wave 41 small intestine absorption 49 cell turnover 83 defence mechanisms 48 fluid flux 56, 57 peristalsis 41 structure 31 transplantation 111 see also duodenum; jejunum smoking colorectal cancer 86, 87 peptic ulcers 74, 75 squamous cell carcinoma 11 smooth muscle 40, 41 sodium–glucose co-transporter (SGLT-1) 51 soft palate 10, 11 solubilization, food 48, 49 somatic nerves 37 somatic sensation 45 somatostatin 19, 22, 23, 42, 43, 57 diarrhoea treatment 67 sorbitol 67 space of Disse 24, 25 sphincter of Oddi 26, 27, 103 dysfunction 70, 71 sphincterotomy 91, 93, 103 sphincters 40, 41, 49 anal 36, 37, 69 manometry 107 spasm 41 see also oesophageal sphincter; pyloric sphincter spider naevi 97 spinal cord, neurological damage 68, 69 splanchnic sympathetic nerve 22, 23, 44, 45 spleen 19 splenic flexure 35 splenic nerve 23 splenic vein 22, 28, 29 splenomegaly 29, 97 spontaneous bacterial peritonitis (SBP) 97 sprue, tropical 31, 78, 79 squamocolumnar junction 36, 37 squamous cell carcinoma 11, 15, 17, 88, 89, 91 squamous epithelium anus 36, 37 mouth 10, 11 oesophageal 16, 17 tongue 14, 15 Staphylococcus aureus 76, 77 starch 49, 50, 51 starvation 51, 55, 84, 85 stasis 79 statins 59 steatorrhoea 23, 27, 51, 67 coeliac disease 83 stellate cells 24, 25 stem cells 19, 20, 21 colonic 35 stents 102, 103 steroids 63, 79 corticosteroids 59, 81, 95, 109 rectal 91 stimulant laxatives 68, 69 stimulation tests 107 stomach 17, 18, 19 digestion 49 formation 38, 39 HCO3- secretion 57 hiatus hernia 72, 73 muscles 18, 19, 41 reflux 72, 73 stomas 110, 111 stones, salivary gland 13 stool bulk 66, 67, 68 bulking agents 68, 69 culture 77, 79 examination 98, 99 history 99 softeners 68, 91 storage vacuoles 25 straining 69, 91 Streptococcus 15, 79 striated muscle 40, 41 stroke 15, 84, 85 sublingual drugs 11 sublingual glands 12, 13 submandibular glands 12, 13 submucosal anal glands 37 submucosal plexus 16, 17, 44, 45 substance P 44, 45 subtotal villus atrophy 82, 83 sucrase 50, 51 sucrose 50, 51 sugars 49, 50, 51 superior mesenteric artery 23, 31, 33, 34, 35, 38, 39 superior mesenteric vein 21, 22, 28, 29, 30, 31, 32, 33, 34, 35, 39 suppositories 37 surface area to volume ratio 48, 49 surgical shunts 28, 29 swallowing 14, 15, 45, 48, 49 difficulties 17, 41 sympathetic nerves 12, 13, 44, 45 dysfunction 70, 71 synchronous wave 41 T cells 47 Taenia 32, 33, 34, 35, 40, 41 Taenia solium 79 Index  119 uploaded by [stormrg] tapeworms 31, 78, 79 taste 13 modalities of 14, 15 receptors 14, 15 sensation 45 taste buds 14, 15 teeth 10, 11, 48, 49 temperature sensation 45 temporalis muscle 10, 11 tenesmus 37, 69, 91 thalamus 64, 65 thermogenesis, adaptive 55 thiamine deficiency 84, 85 thirst 57 thoracic duct 31, 33 thrombocytopenia 29, 97 thrombosis 29, 84, 85 thyrotoxicosis 67 tight junctions 20, 21, 24, 25, 27 epithelial lining 56, 57 tissue transglutaminase (tTG) 82, 83 tobacco chewing 11 tongue 10, 11, 14, 15 sensory nerves 45 tonic contractions 40, 41 tonsillitis 15 tonsils 10, 11, 15, 46, 47 total parenteral nutrition (TPN) 55, 109 touch sensation 45 tow-hit and multiple gene theory 87 toxic megacolon 105 toxins bacterial 57, 66, 67 botulinum 41, 103 enterotoxins 56, 57 exterotoxins 76–7 hepatitis 94, 95 preformed 76, 77 shunting 29 TP53 gene 86, 87 tracheo–oesophageal fistulae 38, 39 tracheo–oesophageal septum 39 tractus solitarius 45 transaminases 59, 61, 95, 98, 99 transamination 60, 61 transcobalamin 52, 53 transcytosis 46, 47 transferrin 52, 53 transforming growth factor  (TGF) 43 transjugular intrahepatic porto-systemic shunt (TIPSS) 28, 29, 104, 105 transplantation 110, 111 transporter proteins 21, 26, 27, 62, 63 trefoil peptides 34, 35 trigeminal nerve 10, 11 triglycerides (triacylglycerols) 49, 50, 51 triradiate fold 32, 33 Tropheryma whipplei 79 120  Index tropical sprue 31, 78, 79 trypsin 49, 50, 51 trypsinogen 49, 50, 51 tuberculosis 33 tubulovillous colonic adenomas 67 tumour necrosis factor  (TNF) 81, 82, 83 typhoid fever 31, 77 ulcerative colitis 33, 35, 37, 79, 80, 81 and diarrhoea 67 proctitis 91 ulcers aphthous 11, 81 duodenal 21, 74, 75 hypertrophic 91 see also peptic ulcers ultrasound scanning 104, 105 endoscopic 101, 103 umbilicus 38, 39 uraemia 15 urea cycle 61, 62, 63 excretion 55 levels 98, 99 urease breath test 75 urine 63 urogenital sinus 38, 39 urorectal septum 38, 39 uveitis 81 vaccines, hepatitis 95 vagotomy 18, 19 selective 74, 75 vagus nerve 16, 17, 18, 19, 23, 44, 45 dysfunction 70, 71 valves of Houston 36, 37 vancomycin 109 varices 29, 96, 97 oesophageal 17, 28, 103 rectal 28 vasoactive intestinal peptide (VIP) 44, 56, 57 vasoactive intestinal peptide (VIP)-secreting tumours 42, 43, 66, 67 vasopressin 57 vegans 53 vermiform appendix 32 vermillion border 10, 11 very low-density lipoproteins (VLDL) 58, 59 vestibulocochlear nerve 64, 65 Vibrio cholerae 67 Vibrio parahaemolyticus 76, 77 villi 48, 49 duodenal 20, 21 jejunal and ileal 30, 31 viral hepatitis 25, 27, 94, 95 cirrhosis 96, 97 Virchow’s node 89 visceral nerves 33 visceral pain 45 visceral sensation 45 vitamin A 24, 25, 52, 53 vitamin B12 52, 53 absorption 19, 48, 49 deficiency 55, 81 digestion 30, 31 Schilling test 106, 107 vitamin B complex 52, 53 deficiency 11, 15, 53 vitamin C 52, 53 vitamin D 52, 53, 55 vitamin E 53 vitamin K 48, 49, 52, 53, 61 vitamins deficiencies 55 digestion 52, 53 voluntary nerves 45 vomiting 17, 41, 64, 65 causes of 64 control 45 and diarrhoea 67 food poisoning 76, 77 vomiting centre 33, 64, 65 waist circumference 85 waist–hip ratio 85 warts, anal 91 wasting 51, 55, 59, 97 water reabsorption 35 water-soluble vitamins 52, 53 weight loss 19, 21, 23, 27, 42, 43 cirrhosis 97 coeliac disease 83 Crohn’s disease 81 history 98, 99 small intestine disorders 31 Werner–Morrison syndrome 43, 89 Wernicke’s encephalopathy 85 Whipple’s disease 78, 79 Whipple’s operation 89 Wilson’s disease 27, 53, 63, 96, 97 wisdom teeth 11 worms 78, 79 X-ray fluoroscopy 105 X-rays 75, 104, 105 xenobiotics 25 xerostomia 13, 15 xylose excretion 106, 107 Yersinia 31, 78, 79 yolk stalk 38, 39 Z-line 16, 17 zinc 53 Zollinger–Ellison syndrome 19, 23, 43, 89 zymogen granules 23 ... throughout the gastrointestinal tract and are also regulated in a typical way Structure The three main pairs of salivary glands are the parotid, submandibular and sublingual glands, and there are many... surfaces of adjacent hepatocytes Tight junctions separate the canalicular membrane from the basolateral surface of the hepatocyte, allowing transport proteins to create and maintain concentration... Darrell Evans of Brighton and Sussex Medicine School co-authored the chapter on Embryology, for which we are grateful List of abbreviations ACh AFP AIDS ALP ALT ANCA APC 5ASA ASCA AST ATP ATPase