What is the presentation of Meckel's diverticulum?

Presentation of Meckel's Diverticulum

Meckel's diverticulum most commonly presents with gastrointestinal bleeding, intestinal obstruction, diverticulitis, and perforation, with bleeding being particularly characteristic in children and young adults. 1, 2

Clinical Presentations

Gastrointestinal Bleeding

• Painless rectal bleeding is a classic presentation, particularly in younger patients 3
• Bleeding occurs due to ulceration of ileal mucosa adjacent to ectopic gastric tissue within the diverticulum 2
• A radionuclide Meckel scan using 99mTc pertechnetate is the diagnostic test of choice for suspected bleeding from Meckel's diverticulum, as it detects ectopic gastric mucosa 3
• Most symptomatic Meckel diverticula with bleeding are found in children and young adults 3

Intestinal Obstruction

• Presents as acute or subacute small bowel obstruction 4
• Accounts for approximately 28.6% of emergency presentations in adults 4
• Obstruction can occur due to:
  • Intussusception (with the diverticulum serving as a lead point)
  • Volvulus around a fibrous band connecting the diverticulum to the umbilicus
  • Entrapment of small bowel beneath a mesodiverticular band 3, 4

Diverticulitis

• Presents with right lower quadrant abdominal pain, mimicking acute appendicitis 4
• Right lower quadrant pain is the most common emergency presentation (31% of cases) 4
• Often associated with fever, nausea, and localized tenderness 2
• CT scan findings include diverticular wall thickening and surrounding inflammatory changes 5

Perforation

• Presents as acute abdomen with signs of peritonitis 6, 4
• Occurs in approximately 18.6% of symptomatic cases 4
• May be secondary to diverticulitis, foreign body, or tumor within the diverticulum 6
• Leads to free intraperitoneal fluid and localized or generalized peritonitis 6

Anatomical and Pathological Features

• Meckel's diverticulum is a true diverticulum containing all layers of the intestinal wall 1
• Located on the antimesenteric border of the distal ileum, approximately 45-60 cm proximal to the ileocecal valve 6, 2
• Average length is about 55 cm 4
• Ectopic tissue is present in 50% of cases:
  • Gastric mucosa (most common) in 42.9% of cases
  • Pancreatic tissue in 5.7% of cases
  • Both gastric and pancreatic tissue in 1.4% of cases 4

Diagnostic Approach

• CT scan of abdomen and pelvis with contrast is highly accurate for diagnosing complications like diverticulitis or perforation 3
• Meckel scan (99mTc pertechnetate scintigraphy) is appropriate in young patients with unexplained lower gastrointestinal bleeding 3
• Negative upper GI endoscopy and colonoscopy in a patient with GI bleeding should prompt consideration of Meckel's diverticulum as a source 3
• Small bowel evaluation may be necessary in cases of obscure GI bleeding when upper and lower endoscopy are negative 3

Clinical Pearls and Pitfalls

• Meckel's diverticulum follows the "rule of 2s":

  • Present in approximately 2% of the population
  • Located within 2 feet of the ileocecal valve
  • Often 2 inches in length
  • Contains 2 types of ectopic tissue (gastric and pancreatic)
  • Most commonly symptomatic before age 2 years 2, 5

• Pitfalls in diagnosis:

  • Often misdiagnosed as appendicitis due to similar right lower quadrant pain 4
  • May be overlooked as a source of GI bleeding after negative upper and lower endoscopy 3
  • Complications can mimic various acute abdominal conditions, leading to delayed diagnosis 2, 5

• Long diverticula are more prone to developing complications 4

• Males are more commonly affected than females (62.9% vs 37.1%) 4

Remember that while many Meckel's diverticula remain asymptomatic throughout life, symptomatic presentations typically require surgical intervention, with resection of the segment containing the diverticulum being the preferred approach 4.