Diagnostic and Therapeutic Challenges of Symptomatic Meckel's Diverticulum in a 61-Year-Old Man With Comorbid Rectal Adenocarcinoma.

Meckel's diverticulum (MD) is the most common congenital anomaly of the gastrointestinal tract, yet it remains a diagnostic challenge in adults due to its non-specific presentation and lower prevalence compared to the pediatric population. We report the case of a 61-year-old man with a history of rectosigmoid adenocarcinoma who presented with recurrent, life-threatening hematochezia from a diverting loop ileostomy. After inconclusive endoscopic and computed tomography (CT) evaluations, mesenteric angiography identified an aberrant omphalomesenteric (vitelline) artery supplying an MD. Following coil embolization for acute hemostasis and subsequent nuclear medicine confirmation, the patient underwent successful surgical resection. This case underscores the importance of maintaining a high index of suspicion for MD in adults with obscure gastrointestinal bleeding.