A bladder fistula is an abnormal connection between the bladder and another organ or skin. The most common forms of bladder fistulas involve:

• The bowel (enterovesical fistula)
• The vagina (vesiovaginal fistula)

Although relatively rare, fistulization to the skin can result from an injury or previous surgery in the face of bladder outlet obstruction. The biggest issue with fistulas is that they are created by infection, and they carry this infection to any organ they connect to. For example, if it tunnels out and connects to the bladder, a bladder infection can develop. Who is at risk for developing a bladder fistula?

• The most common reason for a bladder fistula is an inflammatory bowel disease, such as Crohn’s Disease or diverticulitis. Around 25% of people with Crohn’s Disease will develop a fistula.
• Approximately 20% of bowel fistulas are caused by bowel cancer.
• Fistulas may also develop as a result of previous radiation therapy.

How Does a Bladder Work?

The bladder is a balloon-shaped organ that stores urine, which is made in the kidneys. It is held in place by pelvic muscles in the lower part of your belly. When it isn’t full, the bladder is relaxed. Nerve signals in your brain let you know that your bladder is getting full. Then you feel the need to pee. The brain tells the bladder muscles to squeeze or “contract”. 

Other Types of Urinary Fistulas 

• A vesicovaginal fistula opens between the vagina and the bladder. This is the most frequent kind of urinary fistula in women. This occurs most often because of a previous hysterectomy. Sometimes difficult labor can cause a vesicovaginal fistula.
• An enterovesical fistula opens between the bladder and bowel. This is another of the most common urinary fistulas.
• A vesicouterine fistula opens between the bladder and the uterus.
• A ureterovaginal fistula opens between the vagina and the ureter (the tube that carries urine between the kidneys and bladder). Most ureterovaginal fistulas occur because of prior hysterectomy or other pelvic surgery.
• A urethrovaginal fistula opens between the vagina and the urethra (the tube that takes urine out of the body).
• A colovesical fistula opens between the bladder and the colon.
• A rectovaginal fistula opens between the vagina and the rectum.

Causes

INFLAMMATION

• Inflammation of the lining of the digestive tract causes the intestines to form scar tissue and become abnormally thick.
• This thickening can lead to the formation of ulcers on the inside lining of the intestines.
• When the ulcers grow deeper, they can begin to burrow through the wall of the intestine, forming a tunnel that leads to whatever tissue is next to the sore.

ABSCESSES Anal abscesses are often linked with fistulas and result from an infection of the small glands inside the anus. Crohn’s disease increases the risk of infection of these glands.  

Symptoms

Common symptoms of bladder fistula include:

• Frequent urinary tract infections
• Passage of gas from the urethra during urination
• Urinary leakage

Diagnosis

A doctor may administer the following tests to diagnose a bladder fistula:

• Excretory urogram.- an x-ray examination of the bladder in which contrast dye is injected into the patient’s system and its progress through the urinary tract is recorded to study the anatomy and function of the bladder and urinary tract.
• CT Scan
• Cystogram (bladder x-ray)

Treatment 

A bladder fistula is most often treated with surgery to remove the damaged part of the bladder. Healthy tissue is moved between the bladder and the other organ to block the opening. If the fistula is caused by a disease, such as colon cancer or inflammatory disease, the fistula is fixed during the surgery to treat that disease. 

After Treatment 

A person’s successful surgery is determined on a case-by-case basis. There has to be enough healthy tissue to close the fistula with. Sometimes if cancer is present that cannot be removed during that surgery, or the remaining tissue has poor blood flow due to radiation treatment, the results may vary. Sometimes another surgery may need to be performed. After surgery, you can expect to have some discomfort and you will have a catheter in your bladder for several weeks.