A rare cause of massive rectal bleeding: internal iliac artery aneurysm.

Internal iliac artery aneurysm is a rare cause of lower gastro-intestinal tract (GIT) haemorrhage. A fifty-four year old male patient presented with massive rectal bleeding. Sigmoidoscopy was not conclusive and pelvic angiography revealed an aneurysm from a branch off the main trunk of the anterior division of the right internal iliac artery that was located in juxtaposition to the sigmoid colon. The aneurysm was successfully obliterated by transcatheter arterial embolotherapy with acrylic glue. A high index of suspicion of internal iliac artery aneurysm as a possible cause of lower GIT haemorrhage is of paramount importance. Pelvic angiography is essential for the diagnosis, and embolotherapy with acrylic glue was an effective treatment method in this patient.