Primary Aortoenteric Fistula in a Patient With Prior Abdominopelvic Surgery and Opioid-Induced Constipation.

Aortoenteric fistulas (AEF) represent a rare, life-threatening cause of gastrointestinal bleeding with an incidence of 0.007 per million. Iliac artery-enteric fistulas represent an even more uncommon variant of AEFs. Prompt diagnosis and intervention are required to prevent associated morbidity and mortality. Herein, we report a rare case of iliac-enteric fistula in a patient with hematochezia.