A rare case of Colovesical fistula in a middle-aged man managed successfully by conservative management

Colovesical fistula is an improper connection between the urinary bladder and intestinal tract. Although there are many possible causes of colonovesical fistula, Chen et al. have classified them into five main classes: congenital, traumatic, tumor, inflammatory, and other. Intestinal diverticulitis accounts for 50-70% of cases in Western countries, and nearly all of them are related to colonic or bladder fistulas. Malignant tumors (20%) rank second in Western countries as the most common cause, which are situated largely in the large intestine. Other related tumours include bladder, cervical, ovarian and prostate cancers, and non-Hodgkin's lymphoma in the small intestine. The third most prevalent cause is Crohn's disease (10%), which occurs mainly in the ileum. "Other causes" include iatrogenic injury; trauma; foreign bodies in the intestinal tract; radiotherapy; chronic appendicitis