Colovesical Fistula

For 2 months, a 73-year-old man had experienced dysuria, pneumaturia, and foul-smelling urine. He had an attack of diverticulitis a year earlier. At that time, he underwent a barium enema study, which showed multiple sigmoid colonic diverticula with spasm (A).

Physical examination now disclosed a vague, nontender mass in the left lower quadrant of the abdomen. Flexible sigmoidoscopy was not possible beyond 20 cm from the anal verge, because of extreme narrowing. Urine culture was positive for Escherichia coli. An abdominal CT scan showed air in the dome of the urinary bladder (B, arrow). The sigmoid colon appeared fairly thickened and without active diverticulitis. Cystoscopy revealed an erythematous, edematous area at the dome of the urinary bladder. All of these findings indicated the presence of a colovesical fistula.

The patient underwent sigmoid resection with primary anastomosis, and partial cystectomy with repair of the bladder wall. The pathology report revealed chronic diverticulitis without any malignancy.

Writes Dr Virendra A. Parikh of Fort Wayne, Ind, acquired diverticula of the colon occur in 5% to 10% of persons over age 50, with a progressive increase to 33% among those over age 85. Internal fistulae in diverticular disease are less common, can involve many organs, and have a reputation of being difficult to detect and treat. Colovesical fistula is the most common of these. Surgical resection of the colonic segment with the fistula and repair of the bladder is therapeutic.