1941 Meckel’s Diverticulum in an Adult Presenting as Acute Gastrointestinal Bleeding

Abstract

INTRODUCTION: Meckel’s diverticulum (MD) is the most common congenital anomaly of the gastrointestinal (GI) tract. MD develops as incomplete obliteration of the vitelline duct forms a true diverticulum in the small intestine. It often presents in children as painless rectal bleeding, while adults are often asymptomatic. We are presenting an unusual case of MD in an adult with acute, frank GI bleeding. CASE DESCRIPTION/METHODS: A 35-year-old male presented with one day of bright red blood per rectum (BRBPR), LLQ abdominal discomfort followed by a near syncopal episode. Vital signs were stable on arrival. Physical exam significant for pallor and bright red blood in the rectal vault. Initial hemoglobin was 11.6 g/dl and hematocrit 33.5%. Computed tomography angiogram (CTA) abdomen and pelvis was negative for active bleed. Initial colonoscopy showed gross blood throughout colon without an identifiable source of bleeding. Esophagogastroduodenoscopy was also negative. Patient continued to have episodes of BRBPR with progression to hemorrhagic shock. Hemoglobin and hematocrit the next day decreased to 6.1 g/dl and 17.9%, respectively. However, repeat CTA was negative for active bleeding. Repeat colonoscopy showed blood in the terminal ileum. Technetium 99m pertechnetate scintigraphy demonstrated a focal area of ectopic gastric mucosa in the distal ileum. Laparoscopic small bowel resection was performed with symptom resolution. DISCUSSION: While uncommon in adults, MD should be included on the differential diagnosis of adults with obscure GI bleeding. GI bleeding in MD develops as ileal mucosa is exposed to acid secretion from ectopic gastric mucosa resulting in ulceration in 11.8% of symptomatic adults. Adults often present with melena; hence it is unusual for an adult to present with frank BRBPR. Technetium 99m pertechnetate scintigraphy, also known as Meckel’s scan, is regarded as the modality of choice for diagnosis in the pediatric population, due to its sensitivity of 85%, specificity of 95%, and overall diagnostic accuracy of 90%. Meckel’s scan is less reliable in adults with a sensitivity of 62.5%, specificity of 9% and diagnostic accuracy of 46%. One study illustrated that balloon assisted enteroscopy provided the highest accuracy for diagnosis of bleeding MD in adults and should be considered the preferred modality for preoperative diagnosis. Despite its rarity, awareness and understanding of MD in adults as well as its complications is imperative and may improve patient outcomes.