Clinical Pediatric Gastroenterology: Core Approach
Framing the problem
Pediatric gastroenterology questions reward a disciplined clinical method more than memorized lists. Anchor every vignette on age, growth trajectory, stool pattern, and red flags (bilious vomiting, hematemesis, weight loss, nocturnal symptoms, fever, peritoneal signs).
Concepts to master
- Age-specific differentials: bilious emesis in a neonate is malrotation until proven otherwise; chronic bloody diarrhea in a toddler suggests infectious colitis, milk-protein allergy, or intussusception depending on acuity.
- Growth as a vital sign: distinguish organic from functional causes by crossing weight percentiles, height velocity, and mid-parental target.
- Stool interpretation: osmotic vs secretory diarrhea (fasting response, stool osmotic gap), and steatorrhea suggesting fat malabsorption.
- Red flags vs functional disease: functional abdominal pain lacks growth failure, nocturnal waking, and laboratory abnormalities.
Common traps
Questions often bait you with a normal laboratory panel in a child who is clearly failing to thrive-labs can be normal in early malabsorption. Another trap is attributing bloody stools to allergy when the child has a surgical abdomen. Do not over-order imaging before stabilizing a hemodynamically unstable child.
Worked example
A 3-week-old with projectile non-bilious vomiting, a palpable olive, and hypochloremic hypokalemic metabolic alkalosis: pyloric stenosis. Contrast with bilious emesis in a 3-day-old-malrotation with volvulus, a surgical emergency requiring immediate resuscitation and imaging.
Rule of thumb
Bilious emesis = surgical until excluded; non-bilious projectile emesis in weeks 2–6 = pyloric stenosis.