Description

• Most common congenital abnormality of the GI tract
  • Results from incomplete obliteration of the omphalomesenteric duct in distal ileum
• True diverticula (contains all layers):
  • 50% contain normal ileal mucosa
  • 50% contain either gastric (most common), pancreatic, duodenal, colonic, endometrial, or hepatobiliary mucosa
• Rule of 2’s:
  • 2% prevalence in general population
  • 2% lifetime risk for complications, decreasing with age
  • Symptoms commonly occur around 2 yr of age:
    • 45% of symptomatic patients <2 yr old
  • Average length 2 in
  • Found within 2 ft of the ileocecal valve
• Male-to-female ratio approximately equal, but more often symptomatic in males
• Complications:
  • Obstruction and diverticulitis in adults
  • Hemorrhage and obstruction in children
  • Mean age 10 yr
  • Current mortality rate 0.0001%
  • Occur more frequently in males
• Obstruction:
  • Diverticulum attached to the umbilicus, abdominal wall, other viscera, or is free and unattached, leading to:
    • Intussusception: Diverticulum is the leading edge
    • Volvulus: Persistent fibrous band leads to bowel rotation
• Diverticulitis:
  • Opening obstructed, leading to bacterial infection
  • Presents like appendicitis (most common preoperative diagnosis with Meckel diverticulum)

• Most common cause of significant lower GI bleeding in children
• Presents at age <5 yr with episodic painless, brisk, and bright-red rectal bleeding

Etiology

Remnant of the omphalomesenteric duct that typically regresses by week 7 of gestation. The ectopic gastric mucosa can secrete gastric enzymes, leading to erosion of the mucosal wall, resulting in bleeding.