Rectovaginal fistula secondary to cytomegalovirus rectocolitis in an elderly woman: A case report

Rectovaginal fistula (RVF) is an uncommon but highly morbid condition. Although most nonobstetric RVFs are related to inflammatory bowel disease, malignancy, radiation, or previous pelvic surgery, infectious causes should also be considered. Cytomegalovirus (CMV) usually causes gastrointestinal disease in immunocompromised hosts, but severe rectal involvement has also been described in elderly patients with diabetes or major intercurrent illness. We report the case of a 77-year-old woman admitted for metabolic derangement and urinary sepsis who, during hospitalization, developed rectal bleeding. Colonoscopy showed a circumferential destructive rectal lesion approximately 5 cm from the anal verge, with friable bleeding tissue and suspected fistulous involvement, initially raising concern for rectal cancer. Gynecologic assessment confirmed a rectovaginal fistula. Histopathologic examination of multiple rectal biopsies demonstrated CMV rectocolitis and excluded malignancy. Because of the fistula, recurrent infectious complications, the patient’s frailty, and her social vulnerability, combined medical and surgical management was adopted, including antibiotic therapy, valganciclovir, and fecal diversion by diverting loop colostomy, followed by subacute care and stoma management training. This case highlights two diagnostic pitfalls: CMV rectocolitis may mimic a rectal neoplasm, and fistulizing disease can occur even in patients without documented major immunosuppressive conditions. CMV infection should therefore be included in the differential diagnosis of destructive rectal lesions and rectovaginal fistula.