Adult Meckel diverticulum can present atypically compared to classic childhood Meckel diverticulum. Given the increased likelihood of concurrent medical conditions in adults, it is often overlooked in the differential for lower gastrointestinal bleeding. We report a 61-year-old male with rectal adenocarcinoma status post low anterior resection and diverting loop ileostomy who presented repeatedly with hematochezia via the ostomy. Prior episodes were managed conservatively. During the index admission, esophagogastroduodenoscopy and ileoscopy did not identify a bleeding source; a clip was placed near the suspected site. Interventional radiology was consulted for mesenteric angiography. Superior mesenteric angiography demonstrated a tortuous aberrant ileal branch extending beyond the vasa recta arcade with a focal vascular blush in the right lower quadrant—findings suspicious for a persistent omphalomesenteric (vitelline) artery supplying a Meckel diverticulum. Selective embolization of the culprit branch achieved immediate hemostasis, with resolution of bleeding and an uncomplicated recovery. A post-embolization Tc-99m pertechnetate scan subsequently confirmed Meckel diverticulum. This case highlights that, in adults with lower gastrointestinal bleeding of unclear etiology—including bleeding through an ileostomy—Meckel diverticulum remains an important, albeit uncommon, consideration. Targeted angiography by interventional radiology can both control hemorrhage and suggest the diagnosis.