Severe flank pain radiating to the groin is characteristic of renal colic from calculi, which may present with either gross or microscopic hematuria Crystals may be seen on urinalysis Stones may occur in children with metabolic abnormalities or stasis secondary to obstruction, in premature infants taking furosemide, and children taking topiramate While stones may be visualized by plain radiographs, ultrasound is the preferred method for detection in children due to its ability to detect both radiopaque and radiolucent stones and concerns for radiation expose with CT CT is more sensitive for detecting small ureteral stones Hypercalciuria is an important cause of hematuria in children and may be idiopathic or secondary to another disease and can lead to nephrocalcinosis (see Chapter 100 Renal and Electrolyte Emergencies ) Hematuria that persists after the previously mentioned causes have been ruled out or deemed unlikely on the basis of history and physical examination usually does not require further evaluation in the ED and should be pursued by the primary health care provider, possibly in collaboration with a pediatric nephrologist These additional causes are listed in Figure 36.1 and Table 36.1 and may require more extensive imaging and interventions such as renal biopsy, metabolic studies, or serial urinalyses (benign hematuria, exercise-induced hematuria) Suggested Readings and Key References Bignall ONR 2nd, Dixon BP Management of hematuria in children Curr Treat Options Pediatr 2018;4:333–349 Colleran GC, Callahan MJ, Paltiel HJ, et al Imaging in the diagnosis of pediatric urolithiasis Pediatr Radiol 2017;47:5–16 Cyriac J, Holden K, Tullus K How to use… urine dipsticks Arch Dis Child Educ Pract Ed 2017;102:148–154 Davis TK, Hmiel P Pediatric hematuria remains a clinical dilemma Clin Pediatr 2015;54:817–830 Hynick NH, Brennan M, Schmit P, et al Identification of blunt abdominal injuries in children J Trauma Acute Care Surg 2014;76:95–100