A colovesical fistula is an uncommon condition. It’s an open connection between the colon (large intestine) and the bladder. This can allow fecal matter from the colon to enter the bladder, causing painful infections and other complications.

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. A thick wall of tissue normally separates the colon and the bladder. Surgery or other trauma to this part of the body can cause a fistula to form. When an opening develops, the result is colovesical fistula, also known as vesicocolic fistula.

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

You may become aware that you have a colovesical fistula if you develop one of its most common symptoms including:

  • Pneumaturia. This is one of the most common symptoms. It 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 urine. You will see a brownish color or cloudiness in your urine.
  • Dysuria. This symptom causes a painful or burning sensation when you urinate, and recurrent urinary tract infections (UTI). It can develop from any irritation of the bladder, but nearly half of colovesical fistula cases present with dysuria.
  • 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 half of colovesical fistula cases are the result of diverticular disease.

Other colovesical fistula causes include:

  • colorectal cancer
  • inflammatory bowel disease, particularly Crohn’s disease
  • surgery that involves the colon or bladder
  • radiotherapy (a type of cancer treatment)
  • cancer of other surrounding organs

Diagnosing a colovesical fistula may be done with a cystography, a type of imaging test. During the procedure, your 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, so your doctor can see if there is a fistula.

Another helpful imaging procedure is a barium enema. This can help identify problems with the colon. During the procedure, your doctor inserts a small amount of a liquid containing the metal barium into your rectum through a little tube. 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 with a standard X-ray.

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

The preferred treatment for a colovesical fistula is surgery.

Conservative treatment may be tried if the fistula is small enough, is not due to malignancy, and is in a patient with limited symptoms. Doctors may also recommend conservative treatment when a patient has other illnesses that are so severe, surgery is not considered safe, or when cancer is advanced and inoperable. Conservative treatment may include:

  • being fed through your veins so your intestines do not have to work and can rest
  • antibiotics and steroid medications
  • having a catheter inserted into the bladder to drain fluid that may have seeped into it from the colon

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 is a complication of diverticulitis, make sure you follow your doctor’s orders in treating diverticular disease. In some cases, medications are enough to stop the progression of the condition.

When conservative therapy isn’t appropriate or effective, you’ll need surgery. An operation can remove or repair the fistula and stop the exchange of fluids between the bladder and the colon.

The type of surgery required to treat a colovesical fistula depends on the etiology (cause), severity, and location of the fistula. Typically, for these cases, doctors use a kind of surgery called a sigmoid colectomy. This surgery involves the removal of part of the lower colon. The procedure also includes removal of the fistula itself, and a patching up of the colon and bladder.

The operation may be done with open surgery. Doctors either make a large incision in the belly, or go in laparoscopically, which involves special, thin surgical tools and a few small incisions. Laparoscopic surgery is being used more often for this procedure because it makes for a faster recovery and reduced complication risk. In one study, the average time of laparoscopic surgery to repair a colovesical fistula was just over two hours.

Surgical repair with either approach includes:

  • lying on a surgical table with feet in stirrups (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
  • surgical removal of the fistula (a procedure known as a resection)
  • repair of any defects or injury to the bladder and/or colon
  • 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

An Australian study of laparoscopic colovesical fistula repair found that the average hospital stay after the surgery was six days. Within two days, normal bowel function returned. A case study of a 58-year-old man who underwent open surgery to treat a colovesical fistula found that he was feeling well two days after the operation. He passed clear urine two days later, too.

Your doctor will prescribe antibiotics regardless of the type of surgery or surgeries you undergo.

You should be up and walking the day after your surgery. If there were complications, however, you may be advised to remain in bed for an extra day or two. If the surgery was successful, you should be able to resume normal activities, such as walking up stairs and driving, within a week or two. As with any surgery in the abdominal area, you should avoid lifting anything heavy for a couple of weeks. Be sure to talk with your doctor about any limitations on your activities.

You will probably be given a clear-liquid diet in the first day or so after surgery. Then you will move up to soft foods, and then to a normal diet. If you have diverticular disease, you may be advised to eat a more high-fiber diet. The particulars of your diet will depend on your other health issues. If you’re obese, you will be advised to follow a weight-loss plan including dietary changes and regular exercise.

If you notice an opening of the incisions, significant constipation, bleeding from your rectum, or discolored urine, call your doctor. Pain not related to healing and signs of infection at the incision sites such as redness, warmth, or thick drainage after the surgery should also be reported.

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