A Unique Case of Severe Hematochezia: Ruptured Pseudoaneurysm of the Superior Rectal Artery.

Visceral artery aneurysms are rare, with an incidence of 0.01%-2% based on autopsy results. Among the visceral arteries, inferior mesenteric artery aneurysms are the rarest. To our knowledge, we report the first case of acute lower gastrointestinal bleeding in a 45-year-old man, arising from a nontraumatic pseudoaneurysm of the superior rectal artery, a branch of the inferior mesenteric artery. Urgent angiography provided the diagnosis and allowed successful hemostatic intervention via endovascular coil embolization. A subsequent routine colonoscopy revealed an ulcer with central yellow-bluish bulge in the distal rectum correlating with the site of the treated pseudoaneurysm.