Colovesical fistula often presents with recurrent or persistent urinary tract infection, especially in men. The commonest cause is diverticular disease. Other causes include carcinoma of the colon, Crohn's disease, radiotherapy and trauma. Barium enema may suggest the pathology but cystoscopy is the best investigation to confirm the presence of a fistula. One-stage resection and anastomosis is suitable for most patients with diverticular disease.