A case of acute hemorrhagic rectal ulcer (AHRU) with cytomegalovirus (CMV) enteritis is reported. AHRU is characterized by sudden painless onset of massive hemorrhage from rectal ulcer (s) in patients with serious underlying illnesses. A 70-year-old woman with multiple myeloma was referred to our division for fresh blood in the stool. Endoscopic examination revealed two deep ulcers, one in the lower rectum and the other in the ascending colon. The initial endoscopic diagnosis was AHRU, however, histopathological examination of the biopsy specimen from both ulcers showed evidence of CMV infection. The patient died 22 days later from progression of the multiple myeloma. We reviewed the data of 17 cases (including our case) reported previously from Japan. In conclusion, CMV infection can be a cause or a risk factor for AHRUs.
