A lower abdominal mass, particularly one on the left side, is more often related to chronic functional constipation than to Hirschsprung disease If a mass is found, a careful review of bowel habits is important If an abdominal mass is a fecaloma, a large bolus of stool can usually be felt on rectal examination just inside the anus The evacuation of the impaction, and irrigation of the upper sigmoid colon, should cause the mass to disappear See Chapter 18 Constipation for the causes of constipation Ovarian Masses Simple ovarian cysts and solid teratomas are not uncommon and may be asymptomatic even when large in size Occasionally, the child presents with urinary complaints from the pressure on the bladder or urethra Granulosa cell tumors of the ovary produce precocious puberty because they are hormonally active tumors They may be malignant The sudden onset of severe abdominal pain may indicate torsion of an ovarian mass, with resultant ovarian infarction Radiographs may show calcification in about half of patients with teratomas ( Fig 116.22 ) Because an occasional ovarian tumor is malignant in children, children with ovarian masses should be evaluated promptly and prepared for surgery Omental Cysts Omental cysts are rare, are usually asymptomatic, and can fill the abdomen It is often difficult to differentiate an omental cyst from ascites Smaller cysts are more mobile and can be pushed freely into all quadrants of the abdomen If a cyst volvulizes on its pedicle or has bleeding within it, it may cause abdominal pain or tenderness Elective surgical excision is indicated Mesenteric Cysts Mesenteric cysts can occur anywhere in the mesentery but are most common in the mesentery of the colon They tend to be multilocular and are often discovered during a routine examination or after an episode of abdominal trauma with enlargement from bleeding They are benign, but surgery is indicated, both to confirm the diagnosis and to prevent complications They can usually be removed with sparing of the bowel, or they can be marsupialized into the general peritoneal cavity where the fluid is absorbed