Massive lower gastrointestinal hemorrhage due to primary internal iliac arterial-sigmoid colon fistula.

Primary aortoenteric fistula is a rare entity with high mortality. Depending on the location of the fistula, primary aortoenteric fistulas may lead to upper or lower gastrointestinal hemorrhages. The majority of primary aortoenteric fistulas are associated with atherosclerosis or aneurysms of the aorta, without any previous aortic procedure. Local inflammation, compression, or erosion may lead to rupture of the aneurysm. Owing to difficulties in immediate and correct diagnosis, effective treatment of primary aortoenteric fistulas is often delayed, leading to almost 100% mortality in untreated patients. Here, we report a case of a repetitive mass of lower gastrointestinal hemorrhage due to a primary internal iliac arterial-sigmoid colon fistula. Finally, the patient was managed successfully through endovascular coil embolization.