Sigmoid Diverticulitis - Colovesical Fistula (6 of 8)

The incidence of fistulae in patients with diverticular disease, the most common cause of colovesical fistula, is generally accepted to be 2%, although referral centers have reported higher percentages. Only 0.6% of carcinomas of the colon lead to fistula formation. Colovesical fistulae are more common in males, with a male-to-female ratio of 3:1. The lower incidence in females is thought to be due to interposition of the uterus and adnexa between the bladder and the colon. A 50% previous hysterectomy rate was found among women with colovesical fistulae. In women, other types of fistulae (typically iatrogenic, such as enterovaginal, ureterovaginal, and vesicovaginal) are more common than colovesical fistulae.