Figure 11b. Rectovesical fistulas. (a) VCUG image of a patient with a history of prostatectomy for prostate carcinoma shows a fistula (arrow) with resultant rectal opacification (R). (b) CT cystogram enhanced with intravenous contrast material, obtained in a woman who had undergone suspension of the bladder neck with Dexon mesh (United States Surgical, Norwalk, Conn), shows leakage of contrast material out of the bladder, around the mesh (arrowheads), and into the rectum (R). Transvaginal removal of the mesh was necessary to close the fistula. (c) CT cystogram of another patient shows a fistula with contiguity of the posterior bladder and colonic walls, loss of fascial planes (arrowheads), and leakage of contrast material into the distal sigmoid colon (S) and rectum (R).