A fistula is an abnormal tunnel or connection between two organs in the body, or between the skin and an organ. A fistula forms because of tissue damage. Over time, tissue damage worsens and healthy tissue dies off. This can cause a fistula, or new connection, to form between two spaces in that area. It may take days or years for a fistula to form. In some cases, a fistula is congenital.
The Two Types of Fistulas
A genitourinary fistula forms between the vagina or uterus or a part of the urinary system, such as the bladder, urethra, or ureter. This fistula allows urine to flow into the vagina or uterus, causing urine leakage.
A genitourinary fistula increases the risk of urinary tract and kidney infections. Women may experience the following symptoms:
- Urine odor from the vagina
- Constant or occasional leakage from the vagina
- Skin issues near the vaginal opening due to constant moisture
- Bloating and pelvic pain
- Nausea
- Vomiting
- Poor appetite
A rectovaginal fistula is an abnormal connection between the vagina and rectum, which allows stool to enter the vagina. Symptoms of a rectovaginal fistula include:
- Rectal or vaginal bleeding
- Foul discharge from the vagina
- Sense of air escaping from the vagina
- Recurring vaginal infections
- Accidental bowel leakage through the vagina
Causes of Fistulas
Fistulas may form due to the following causes:
- Childbirth. Long periods of labor may cause pelvic tissue to break down. Tearing during vaginal delivery and Cesarean sections increase the risk of fistulas.
- Cancer. Cancer in the pelvic area or radiation therapy may damage tissue.
- Chronic bowel conditions. Inflammatory bowel disease or diverticulitis may lead to fistulas.
- Pelvic injury. Damage to the pelvic organs and leaving a pessary or diaphragm in for too long can damage tissue.
- Surgery. Pelvic surgery, such as a hysterectomy or pelvic reconstructive surgery, may lead to the rare complication of fistulas.
Diagnosing Fistulas
The physician will perform a thorough pelvic exam to identify the source of pelvic leakage. He or she may use a dye to figure out where the fluid is leaking from.
In a double dye test, the patient may take a pill to turn the urine orange and have a blue dye inserted into the bladder. Then, the patient will insert a tampon into their vagina. If the tampon turns blue, then the patient has a fistula between their bladder and the vagina, called a vesicovaginal fistula. If the tampon turns orange, then the fistula may be between the ureter and the vagina, called a ureterovaginal fistula.
Other tests that may be done to diagnose and identify a fistula include:
- Cystoscopy. During a cystoscopy, the physician inserts a small camera into the bladder and urethra to find the fistula and see how big it is. The outpatient procedure is done without general anesthesia.
- Imaging tests. A computerized tomography (CT) scan may be done to examine the urinary tract. Or, a specialized X-ray, called a retrograde pyelogram, may be done to find the fistula.
- Lab tests. Patients may need to submit a urine sample to check for a urine infection. A blood test may also be done to check kidney function and identify signs of infection.
Treatment for Fistulas
Depending on the size, location, and cause of the fistula, treatment may involve a urethral catheter or surgery. Surgery may involve placing a graft or tissue flap to help the tissues around the fistula heal.