Item does not contain fulltextA 70-year-old man presented with acute lower gastrointestinal bleeding. A colonoscopy performed one and a half months prior had revealed diverticulosis in the sigmoid colon; a small polyp located 10 cm from the anal margin had been removed at that time. The presenting patient was haemodynamically unstable and there was a significant amount of rectal blood loss. Gastroscopy revealed no abnormalities. During angiography, the patient died as a result of haemorrhagic shock. The post-mortem examination revealed a rectal perforation, which had most likely resulted from the polypectomy, and a secondary haematoma located between the common iliac artery and the rectum. The source of the gastrointestinal bleeding was the rupture of the haematoma directly into the rectal perforation. Colonoscopy is a relatively safe procedure; however, this case illustrates that potentially lethal complications from colonoscopy can be expressed, even after a few months