Meckel's diverticulum (MD), the most prevalent congenital anomaly of the GI tract, arises from incomplete obliteration of the vitelline duct during embryogenesis. Though often asymptomatic, MD can cause complications like bleeding, obstruction, or inflammation. Diagnosing MD in adults is difficult due to its rarity and symptom overlap with other GI conditions. Modern imaging, particularly the technetium-99m pertechnetate scan (Meckel's scan), has improved detection capabilities. This case report explores an adult with obscure GI bleeding linked to MD, focusing on diagnostic and therapeutic challenges. A 42-year-old male presented with a short history of melena and visible red blood in his stools. Initial esophagogastroduodenoscopy (EGD) and colonoscopy at an outside facility failed to identify the bleeding source. Laboratory tests showed severe anemia, prompting a transfusion of packed red blood cells. Despite treatment for a concurrent Clostridium difficile infection, bleeding continued. Further tests, including capsule endoscopy, computed tomography angiography (CTA), mesenteric angiography, and a repeat EGD extending to the jejunum, revealed no clear cause. Due to persistent bleeding, a Meckel's scan was performed, showing mid-abdominal uptake suggestive of MD. Exploratory laparotomy confirmed MD with mesenteric adhesions, and surgical resection of the affected bowel segment was carried out. The patient recovered smoothly and was discharged post-surgery without issues. While a frequent cause of GI bleeding in children, MD is often overlooked in adults due to its rarity and vague symptoms, such as bleeding, obstruction, or inflammation. The Meckel's scan, which identifies ectopic gastric mucosa, is less effective in adults than in children but remains useful. Surgical resection is the standard treatment for symptomatic MD. This case emphasizes the importance of considering MD in the differential diagnosis of unexplained GI bleeding when routine tests are inconclusive. Timely diagnosis and intervention are essential to reduce ongoing blood loss and complications. This report highlights the diagnostic difficulties of obscure GI bleeding in adults and supports a multidisciplinary approach to improve outcomes.