Pseudoaneurysm of the internal iliac artery resulting in massive per-rectal bleeding

Rectal bleeding is a common reason for presentation to hospital, with large bleeds most commonly caused by diverticular disease and angiodysplasia. Here we present an unusual aetiology of massive per-rectal bleeding attributable to pseudoaneurysm of the internal iliac artery leading to an arterial fistula to the distal large bowel. It is hoped the case will serve as a reminder that rectal bleeding can have a less common aetiology.