<s>[INST] context: Colovesical fistulaA colovesical fistula is the presence of a communication between the lumen of the CausesDiveiculitis:Crohn&;s disease: ~ 10%RadiotherapyTraumaClinical presentationRadiographic featuresIn most instances, the diagnosis is suspected clinically due to pneumaturia, faecaluria, recurrent urinary tract infections, or passage of urine rectally.In some cases, it will be first diagnosed radiologically at the time of investigation for the primary diseaseCT scan - Presence of gas within the lumen of the bladder. Contrast may be instilled into the rectum &;on table&; prior to the acquisition of images in order to demonstrate a fistulaFluoroscopy Treatment and prognosisSurgical resection of the fistula and abnormal segment of bowel is usually required for cure, although in the setting of malignancy this suggests advanced disease (T4) making surgery complex.In such cases, if palliation only is required then de-functioning colostomy, colonic stent placement or a nephrostomy may be required.(Refer: [/INST] question: Colovesical fistula | options: A: Most commonly presents with pneumaturia B: More common in females C: Most commonly caused by colon cancer D: Readily diagnosed on barium enema | answer: A </s>