A colovesical fistula is an open connection between the colon and bladder. A thick wall of tissue normally separates the two.

Fecal matter from the colon can enter the bladder through this colovesical fistula, causing painful infections and other complications.

Colovesical fistulas are uncommon. They’re also known as vesicocolic fistulas.

The colon, which helps form stool to be released through the rectum, sits above the bladder. The bladder stores urine before it’s released through the urethra. Surgery in, or other trauma to, this part of the body may cause a fistula to form.

A colovesical fistula is treatable. However, because it’s so unusual, there’s a limited amount of information about how best to manage it.

You may become aware that you have a colovesical fistula if you develop one of its most common symptoms, which can include:

  • Pneumaturia. Pneumaturia occurs when gas from the colon mixes with urine. You may notice bubbles in your urine.
  • Fecaluria. This symptom occurs when you have a mixture of fecal matter in your urine. You’ll see a brownish color or cloudiness in your urine.
  • Dysuria. Dysuria is a painful or burning sensation when you urinate. This symptom can be a result of a urinary tract infection (UTI). Dysuria can also develop from any irritation of the bladder.
  • Hematuria. This symptom occurs when you have blood in your urine. Traces of blood that you can see are described as gross hematuria. When blood can only be seen with a microscope, it’s called microscopic hematuria.

Diarrhea and abdominal pain are also common symptoms.

More than two-thirds of colovesical fistula cases are the result of diverticular disease, according to StatPearls.

Other colovesical fistula causes include:

Doctors may rely on CT scans to help diagnose colovesical fistula. They’re accurate at least 90 percent of the time.

A doctor can also use cystoscopy, another type of diagnostic technique.

During the procedure, the doctor inserts a thin, flexible tube with a camera at one end into your bladder. The camera relays images of the bladder wall to a computer, allowing the doctor to see whether there’s a fistula.

Another helpful imaging procedure is a barium enema, which the doctor may use to identify problems with the colon.

During the procedure, the doctor uses a little tube to insert a small amount of a liquid containing barium, a metal, into your rectum. The barium liquid coats the inside of the rectum, allowing a special X-ray camera to see the soft tissue in the colon in greater detail than is possible with a standard X-ray.

Images of the fistula, along with a physical exam, urine specimen, and a review of other symptoms, can help the doctor diagnose a colovesical fistula.

The preferred treatment for a colovesical fistula is surgery.

Conservative treatment, which is nonsurgical, may be reserved for people who cannot tolerate the surgical procedure or who have extensive unresectable cancer. If a cancer is unresectable, that means it cannot be removed through surgery.

Conservative treatment may include:

The goal of conservative treatment is for the fistula to close and heal on its own. However, surgery may still be necessary in cases where the fistula does not heal on its own.

Because colovesical fistula may be a complication of diverticulitis, make sure you follow the doctor’s orders in treating diverticular disease. In some cases, medications are enough to stop the progression of diverticulitis.

When conservative therapy is not appropriate or effective, you’ll need surgery. A surgeon can remove or repair the fistula and stop the exchange of fluids between the colon and bladder.

The cause, severity, and location of the fistula will determine which type of surgery is used to treat it. Since colovesicular fistulas are found most commonly between the sigmoid colon and bladder, doctors often perform a kind of surgery known as a sigmoid colectomy.

This surgery involves the removal of part of the sigmoid colon, the last section of the colon. The procedure also includes removal of the fistula itself and a patching up of the colon and bladder.

Surgical methods

The operation may be performed in one of two ways:

  • with open surgery, where a doctor makes a large incision in the abdomen
  • laparoscopically, which involves special, thin surgical tools and a few small incisions

Other techniques include endoscopic repair or robotic surgery.

A small 2013 study involving 15 people found that operating times for laparoscopic management of diverticular colovesical fistula ranged from 85 minutes to 4 hours.

A 2014 literature review looked at laparoscopic treatment of colovesical fistulas associated with complicated sigmoid diverticular disease. Operating times ranged from 2.5 hours to 5 hours and 21 minutes.


Surgical repair with either approach may include these steps:

  • lying on a surgical table with the feet in stirrups, which is known as the lithotomy position
  • general anesthesia
  • an open surgery incision or multiple laparoscopic incisions
  • separation of the colon and bladder, which are moved farther apart to continue the procedure
  • a bowel resection, which is the surgical removal of the part of the bowel that contains the fistula
  • repair of any defects or injury to the colon or bladder
  • relocation of the colon and bladder to their proper positions
  • placement of a special patch in between the colon and bladder to help prevent future fistulas from forming
  • closure of all incisions

A small Australian study of laparoscopic colovesical fistula repair found that the median hospital stay after the surgery was 6 days. Within 2 days, normal bowel function returned.

If the surgery was successful, you should be able to resume normal activities, such as walking up stairs and driving, within a couple of weeks.

Be sure to talk with the doctor about any limitations on your activities, including lifting of heavy objects. Also discuss with your doctor if and when you may need antibiotics.

Your diet

You may be encouraged to follow a clear liquid diet for the first day after your surgery. Then you’ll move on to soft foods and then to a normal diet. If you have diverticular disease, you may be advised to eat a diet that’s higher in fiber.

The particulars of your diet will depend on whether you have any other health issues. If you have obesity, you’ll be advised to follow a weight-loss plan, including dietary changes and regular exercise.

When to see a doctor

Make sure to ask your doctor when you should call or be evaluated and what to watch out for.

Consult with your doctor if you have any questions or concerns. Some reasons to call your doctor include:

Though it may be painful, a colovesical fistula can be treated successfully. The same is true for many of its underlying causes, such as diverticular disease. Though you may need to change your diet and lifestyle, these conditions and their treatments should not cause any long-term complications.