This 83-year-old patient was admitted to the emergency room after a sudden and abundant rectal bleeding without any other abdominal symptoms. The physical examination showed normal abdominal findings. However, digital rectal examination revealed dark red blood. Upper and lower endoscopic examination did not show an active bleeding source. A diagnosis of an acute lower gastrointestinal bleeding probably originating from a diverticulum was made. The patient was dismissed two days later without any signs of further bleeding. However, the same day he was readmitted again because of acute rebleeding. Emergency colonoscopy was not conclusive because of massive hemorrhage. Angiography of the abdominal arteries was performed which showed marked active bleeding in the coecal region. Ileocoecal resection was performed and histopathological examination showed a solitary coecal diverticulum.