Obscure Gastrointestinal Bleeding with Elusive Meckelʼs Diverticulum

Abstract

Purpose: Obscure gastrointestinal tract bleeding can be particularly worrisome, as even after judicious testing, the etiology is not always certain. Meckel's diverticulum is a remnant of the viteline duct affecting about 2% of the population, making it the most prevalent congenital abnormality of the GI tract. It contains ectopic tissue of gastric and pancreatic predominance whose respective acidic and alkaline secretions can ulcerate tissue and cause hemorrhage. Around 90% of the diverticuli are within 90cm of the ileocecal valve. Results: 20-year-old healthy male with no past medical history was admitted for 4 episodes of painless rectal bleeding for one day. Slight nausea was present, but no emesis, fevers, abdominal pain or constitutional symptoms. No family history of colorectal cancer or IBD. Hemoglobin was 12.8. Colonoscopy showed blood throughout the entire colon and distal ileum, with ileal biopsy normal. EGD was unremarkable. Capsule endoscopy revealed small patches of hematin in distal intestine but no active bleeding source identified. There was no clear etiology of the bleeding and a presumed diagnosis of Dieulafoy's lesion was made. He was discharged and two days later, re-presented with continued rectal bleeding but was also severely anemic—hemoglobin 5.4. Colonoscopy and EGD was repeated showing blood throughout the colon and at the terminal ileum. Mesenteric angiogram showed no evidence of bleeding. Meckel's nuclear scan was performed showing no ectopic gastric mucosa. As the source of the rectal bleeding was not identified, exploratory laparotomy with push enteroscopy was performed, revealing an actively bleeding Meckel's diverticulum in the distal ileum along with suspected arteriovenous malformation in the distal jejunum. Diverticulectomy along with segmental small bowel resection was performed and afterwards bleeding resolved. Pathology confirmed Meckel's diverticulum with an ulceration extending into a submucosal artery. The acute anemia was treated with 10 units of RBC. Conclusion: Meckel's diverticulum is difficult to diagnose with nonspecific symptoms and can mimic a number of common conditions such as gastroenteritis, biliary colic, PUD, milk allergy, colonic diverticulitis. Complications include SBO, bleeding, intussusception and diverticulitis. CT scans are often nonspecific and arteriography is not always diagnostic because the arterial supply may not show any abnormalities. Technetium-99m scanning is the most useful test as it accumulates in gastric mucosa but sensitivity is only 62.5%, specificity 9%, in adults. This case illustrates the diagnostic importance of persistence in making a diagnosis of Meckel's diverticulum because of the insensitivity of current diagnostic modalities.