Classic triad: colicky pain + vomiting + bloody stool. Peak 5-9 months.

Projectile non-bilious vomiting in 2-12 week old, 4-5x more common in males

Bilious vomiting in neonate/infant = malrotation until proven otherwise

Most common surgical cause of acute abdominal pain in children. Pain migration from periumbilical to RLQ is classic.

Often follows viral URTI. Pain less localized than appendicitis. Self-limiting.

Most common medical cause of acute abdominal pain. Diarrhea is prominent.

Most common cause of acute abdominal pain in primary care (35% of cases). Palpable fecal mass.

Rome IV: ≥4 episodes/month for ≥2 months, not meeting IBS/dyspepsia/migraine criteria, no organic cause

Rome IV: Pain related to defecation or stool changes. Subtypes: IBS-C, IBS-D, IBS-M

Rome IV: Epigastric symptoms not related to bowel habits. Two subtypes: PDS and EPS

Intense episodic periumbilical pain with vasomotor symptoms and pain-free intervals

33% worldwide prevalence in children. Mother-to-child transmission most common. Test-and-treat only if symptomatic.

Autoimmune response to gluten. tTG-IgA >10x ULN + positive EMA can diagnose without biopsy.

Chronic bloody diarrhea + growth failure + elevated inflammatory markers. Perianal disease suggests Crohn.