Congenital GIT Anomalies
Gastrointestinal tract anomalies often stem from errors in recanalization, migration of neural crest cells, or closure of embryonic structures.
| Anomaly | Pathophysiology / Presentation |
|---|---|
| Esophageal Atresia/Fistula | Failure of the tracheoesophageal septum to divide. Presents with polyhydramnios, drooling, and choking/cyanosis on feeding. |
| Hypertrophic Pyloric Stenosis | Hypertrophy of pyloric smooth muscle. Presents with “olive-sized” mass and non-bilious, projectile vomiting in infants. |
| Hirschsprung Disease | Failure of neural crest cells to migrate. Leads to the aganglionic distal colon (Auerbach/Meissner plexus). Bilious vomiting, failure to pass meconium. |
| Meckel Diverticulum | Persistence of the vitelline duct. Can contain ectopic gastric/pancreatic tissue. Follows “Rule of 2s.” |
High-Yield Clinical Pearls:
- Bilious vs. Non-bilious: Vomiting distal to the Ampulla of Vater is usually bilious. Pyloric stenosis is proximal, hence non-bilious.
- Malrotation: Often leads to midgut volvulus; look for “Ladd’s bands” compressing the duodenum.