Pediatric Gastroenterology and Hepatology
This domain tests reflux and constipation, the recognition of surgical emergencies presenting as GI symptoms, and the cholestatic infant.
Reflux and constipation
- Physiologic gastroesophageal reflux peaks at about 4 months and resolves by 12 months; it needs no acid suppression.
- GERD implies poor weight gain, esophagitis or hematemesis; treat with a proton pump inhibitor and feeding modification.
- Functional constipation is treated with polyethylene glycol disimpaction and maintenance, plus toilet training.
Malabsorption and inflammation
- Celiac disease: tissue transglutaminase IgA with a total IgA level, confirmed by duodenal villous atrophy; manage with a lifelong gluten-free diet.
- Crohn disease: skip lesions, transmural inflammation, granulomas, perianal disease. Ulcerative colitis: continuous mucosal disease starting in the rectum with bloody diarrhoea.
Surgical presentations
- Intussusception: 6-36 months, intermittent colicky pain, red-currant-jelly stool, target sign on ultrasound; air enema reduction is first line.
- Hirschsprung disease: failure to pass meconium within 48 hours, explosive stool, transition zone on contrast enema, confirmed by rectal biopsy.
Cholestasis
- Biliary atresia presents with jaundice beyond 2 weeks, pale stools, dark urine and a direct bilirubin above 1 mg/dL. The Kasai portoenterostomy must be performed before 60 days of age for best outcome.
- Wilson disease after age 3: liver disease, neuropsychiatric signs, Kayser-Fleischer rings, low ceruloplasmin.
Worked example
A 2-month-old is still jaundiced with pale stools. Direct bilirubin is 6 mg/dL. Reasoning: conjugated hyperbilirubinemia is never breast-milk jaundice. Obtain ultrasound and hepatobiliary scintigraphy urgently and refer for Kasai before 60 days.
Traps
Calling breast-milk jaundice pathologic (it is unconjugated and benign); forgetting to fractionate bilirubin in prolonged jaundice; and treating constipation with repeated enemas instead of an osmotic laxative.