[Internal iliac artery aneurysm rupture with aorto-enteric fistula after reconstruction of abdominal aortic aneurysm: report of a case].

An 84-year-old male was admitted to our hospital due to diarrhea. Fourteen years ago, he underwent a graft replacement for an abdominal aortic aneurysm. Three years ago, he was pointed out left internal iliac artery aneurysm about 8cm in diameter. During the hospital stay, he experienced sudden massive hematochezia. Colonoscopic examination revealed a fistula at the rectum. Abdominal CT showed left internal iliac artery aneurysm with aorto-enteric fistula (AEF). An emergent aneurysmectomy and Hartmann's procedure was performed and the patient recovered. This case might show the usefulness of colonoscopy and CT for early diagnosis of secondary AEF. Early diagnosis and surgical treatment are necessary to recover from secondary AEF.