Appearance of a colovesical fistula at cystoscopy.

Colovesical fistulae typically present with pneumaturia and/or fecaluria. Diverticulitis, inflammatory bowel disease, and malignancies of the colon are the commonest causes. The fistulous tract and adjacent organs are best demonstrated by contrast-enhanced CT scan with rectal contrast or MRI. Biopsy at cystoscopy/colonoscopy is necessary for complete evaluation and treatment planning.

Questions

What study is this and what is being shown?

What are the typical symptoms and causes?

What is the best radiological study to confirm the diagnosis?

This is a colovesical fistula, seen at cystoscopy, in a man with diverticulitis. Congested and erythematous urothelium is seen, with oedematous mucosa in the centre emitting mucus and gas.

Pneumaturia, fecaluria, and recurrent polymicrobial urinary tract infections are classic features. The commonest cause is diverticulitis 1. Other causes include inflammatory bowel disease, large bowel tumors, radiation, surgical trauma, foreign body, and chronic specific infections such as actinomycosis and tuberculosis.

An abdominopelvic CT scan with oral, rectal, and intravenous contrast is the imaging modality of choice to diagnose and characterize a colovesical fistula 1, although recently the accuracy of MRI has been reported to approach 100% 2.

Conflicts of Interest

None declared.