A 65-year-old man presented to the emergency department with a chief complaint of “it whistles when I pee.” The patient complained of a two-day history of gross hematuria and dysuria but denied flank, back, and abdominal pain. He described a two-week history of air coming from the urethral meatus at the end of urination.
He also reported that he had been treated with ciprofloxacin for two weeks for a urinary tract infection, which he finished one week prior to presentation. The patient had been seen five months previously with diverticulitis and perforation, resulting in a small abscess that responded to conservative treatment with IV antibiotics. The patient's history was also significant for a gunshot wound to the abdomen 39 years before, which was treated with exploratory laparotomy, small bowel resection, and primary anastomosis.
He had no abdominal tenderness or genitourinary or other abnormalities. Urinalysis was positive for large amounts of blood, protein, nitrites, bacteria, and leukocyte esterase. A CT scan of the abdomen with contrast demonstrated evolving diverticular abscess with tiny connections between the sigmoid colon lumen and lumen of the bladder, which represents fistula formation. Evidence of cystitis and air in the bladder was also seen. The patient was started on IV piperacillin-tazobactam in the emergency department and was evaluated by surgery, resulting in admission to the hospital for corrective surgery the next day.
He subsequently underwent cystoscopy, retrograde pyelogram with left ureteral stent placement, and cystogram, which revealed bladder hyperemia but no active fistula. The patient was taken to surgery the next day for open sigmoidectomy with anastomosis, rigid proctoscopy, removal of ureteral stent, and primary closure of posterior peritoneal defect. Intraoperatively, they discovered significant diverticular disease with adhesions of the sigmoid diverticula to the posterior bladder, but were unable to identify a transmural bladder defect. Unfortunately, an anastomotic leak occurred one week after surgery, and he was taken back to the operating room for emergent Hartmann's procedure with colostomy creation. The patient's status improved on various antibiotics over the next several days, and he was discharged in stable condition. Diverticular disease is the most frequent cause of colovesical fistulas. Fistula formation complicates up to 20 percent of surgically-treated cases of diverticular disease, and the most common fistula formation is colovesical. (Dis Colon Rectum 1988;31;591.)
Common symptoms of colovesical fistula include pneumaturia, dysuria, irritation, and fecaluria because of passage of stool and gas from the urethra. Urinalysis is consistently abnormal with cultures revealing polymicrobial growth. Diagnosis is obtained by computed tomography, barium enema, colonoscopy, cystoscopy, poppy seed test, or IV urography. Direct visualization of the fistula with barium enema and endoscopy is uncommon; studies demonstrate a yield of 20 to 26 percent and 0 to 3 percent, respectively. (Am J Surg 1987;153;75; J Urol 1995;153;44.) CT is also unlikely to demonstrate the fistula directly, but can suggest a fistula diagnosis with thickened bladder and thickened adjacent colon with air or contrast material in the bladder. These findings are sensitive and specific for colovesical fistula from diverticular disease. (J Urol 1995;153;44.)
Treatment is almost invariably surgery because fistulas do not generally close on their own. The majority of cases can be treated with one-stage elective resection and primary anastomosis with the bladder portion of the fistula being pinched off without visible defect. (Am J Surg 1987;153;75.)
Patients with colovesical fistulas may present with a variety of complaints, but pneumaturia, fecaluria, and dysuria are nearly pathognomonic. This patient's unique presentation of “it whistles when I pee” and the associated hematuria and flank pain suggested an initial diagnosis of colovesical fistula. A CT scan of the abdomen and pelvis helped reinforce this diagnosis, but it was not definitive.
The literature suggests that the poppy seed test had the highest sensitivity to detect colovesical fistula. This involves oral intake of 50 g of poppy seeds mixed in a beverage or yogurt followed by visual inspection of repeated urine samples over the next 48 hours. Detection of seeds in the urine indicates a positive test. One study found the poppy seed test detected 94.6 percent of colovesical fistulas compared with just 61 percent diagnosed by CT. Computed tomography, colonoscopy, and cystoscopy are still essential in suspected colovesical fistula to diagnose possible underlying carcinoma of the colon or bladder. (J Urol 2009;182;978.)
The fistula was not visualized surgically in this case, but resection and anastomosis were performed for a presumed fistula. A conservative approach to management may have also produced satisfactory results. One retrospective study demonstrated no occurrence of septicemia or decline in renal function in those treated conservatively without surgery suggesting this as a viable option. (Colorectal Dis 2005;7;467.)
A colovesical fistula diagnosis is often presumed based on symptoms and urinalysis. A more definitive diagnosis is suggested with a CT scan of the abdomen and pelvis. Other modalities can also lead to this diagnosis, including the poppy seed test, colonoscopy, and cystoscopy, but care needs to be made to exclude other underlying causes of the fistula. Managing the fistula can be accomplished conservatively or surgically with similar outcomes.