A Case of Rectovesical Fistula due to Rectal Diverticulitis Treated in Two-Stage Operation

We report an uncommon case of a rectovesical fistula due to rectal diverticulitis treated in two-stage operation. The patient was a 62-year-old man who was admitted for abdominal distention and pneumaturia. Abdominal computed tomography showed bowel obstruction and a rectovesical fistula due to a rectal tumor. We performed a colostomy on the basis of the diagnosis of ileus due to a rectal tumor. Postoperative examinations led to a diagnosis of rectovesical fistula due to rectal diverticulitis. Conservative observation (oral administration of levofloxacin hydrate: 500 mg/day+meloxicam: 10 mg/day) was chosen because malignancy was not suspected. During the observational period, the inflammation and pneumaturia resolved. We performed two-stage operation (partial resection of the rectum) 5 months after the first operation. During the operation, we found that the degree of adhesion between the rectum and bladder was not as severe as expected and that the rectovesical fistula had disappeared. The findings for the resected specimen suggested that the rectovesical fistula had been caused by rectal diverticulitis. Because a rectovesical fistula due to rectal diverticulitis is a benign disease, the use of invasive procedures should be kept to a minimum in such cases. The two-stage operation was very effective for the treatment of the rectovesical fistula. Therefore, we present this rare case of rectovesical fistula due to rectal diverticulitis with a review of the literature.