A case of colovesical fistula caused by the eroded rectal stent

A 59-year-old man with squamous cell carcinoma of the anus diagnosed and treated with wide local excision followed by chemotherapy and pelvic radiation in 2008 presented 4 years later with constipation. Colonoscopy revealed rectosigmoid stricture for which the patient underwent balloon dilation and colonic stent placement. Biopsy results were negative for tumour recurrence. After stent placement, the patient had been admitted several times with rectal pain with the most recent one being 1–2 months before. That time, colonoscopy did not show any stent malfunctioning, and biopsy was negative for malignancy and diverticulitis. This time the patient presented complaining of dysuria, frequency and fecaluria accompanied by abdominal pain for several weeks. Urine analysis showed pyuria, bacteria and positive nitrite. A …