A urinary fistula is an abnormal opening that connects part of the urinary tract to another organ or the skin, allowing urine to leak where it shouldn’t. These openings can form between the bladder and the vagina, the ureter and the vagina, the bladder and the uterus, or even between the bladder and the bowel. The result is often continuous, uncontrollable urine leakage that significantly affects daily life.
Types of Urinary Fistula
Urinary fistulas are named based on which two structures the abnormal connection links. The most common type in women is a vesicovaginal fistula (VVF), a hole between the bladder and the vagina. A ureterovaginal fistula connects one of the ureters (the tubes that carry urine from the kidneys to the bladder) to the vagina. A vesicouterine fistula links the bladder to the uterus. Less commonly, a fistula can form between the bladder and the bowel, or between the urethra and the skin surface.
Size and location matter for prognosis. Fistulas smaller than 4 cm that involve only the bladder wall, with no scarring or tissue loss, are considered simple and carry a good outlook for repair. Complicated fistulas are those larger than 4 cm, involve multiple openings, affect the urethra or cervix, show significant scarring, or have had a previous failed repair.
What Causes a Urinary Fistula
In high-income countries, the leading cause is accidental injury during pelvic surgery. In a study of 634 fistula patients, 58.5% had fistulas caused by surgical procedures. Among those, hysterectomy was responsible for 52.5% of cases, cesarean hysterectomy for 26.4%, and cesarean delivery for 19.9%. During these surgeries, instruments or incisions can inadvertently damage the thin wall separating the bladder or ureter from surrounding structures.
In low-resource settings, the picture is very different. Prolonged, obstructed labor is the primary cause. When labor stalls for hours or days without access to a cesarean section, the baby’s head presses against the mother’s pelvic tissues, cutting off blood supply. The tissue dies, and a hole forms between the birth canal and the bladder or rectum. The World Health Organization estimates that more than 2 million women in sub-Saharan Africa and Asia are living with untreated obstetric fistula, and 50,000 to 100,000 new cases develop each year.
Other causes include radiation therapy to the pelvis (which can weaken tissue over time), inflammatory bowel conditions like Crohn’s disease, pelvic cancers, and traumatic injuries.
Symptoms to Recognize
The hallmark symptom is urine leaking from somewhere other than the urethra. For women with a vesicovaginal fistula, this means continuous or near-continuous wetness from the vagina that doesn’t respond to pads or bathroom habits. The leakage often has a distinct urine smell, and because the skin stays constantly damp, irritation, rashes, and recurring urinary tract infections are common. Some people notice the leaking started shortly after a surgery or difficult delivery, which is an important clue.
With a ureterovaginal fistula, you may still urinate normally through the urethra while also leaking from the vagina, because only one ureter is affected and the bladder continues to fill and empty on its own. Fistulas between the bladder and bowel can cause air bubbles in the urine or repeated urinary infections with unusual bacteria.
How Urinary Fistulas Are Diagnosed
Doctors often start with a physical exam and a simple dye test. A colored dye is placed into the bladder through a catheter while a tampon or gauze is positioned in the vagina. If the tampon turns blue (from the dye), the fistula connects the bladder to the vagina. If the tampon instead turns orange (from a separate pill that colors urine orange as it passes through the kidneys), the fistula likely connects a ureter to the vagina. Both colors appearing together suggests two fistulas are present.
CT scans are the most commonly used imaging tool, with diagnostic accuracy ranging from 60% to 100% depending on the fistula’s size and location. CT scanning can show the exact position of the opening and whether surrounding tissues are involved. MRI is sometimes used for complex cases, but it hasn’t been shown to offer clear advantages over CT for most fistulas and is typically reserved as a second-line option.
Treatment Without Surgery
Very small fistulas sometimes heal on their own with the right support. Research suggests that simple fistulas with a diameter under 0.5 cm, particularly vesicouterine fistulas, can be treated conservatively. The approach involves keeping the bladder continuously drained with a catheter so urine doesn’t flow through the fistula, giving the tissue a chance to close. Patients are also encouraged to stay well hydrated and maintain good nutrition to support tissue healing.
In reported cases, patients with fistulas at or below 0.5 cm recovered after about two months of catheter drainage. If there’s no improvement by that point, surgery becomes the next step. Conservative management is not an option for larger fistulas or those with significant scarring.
Surgical Repair
Most urinary fistulas require surgery to close the abnormal opening. Surgeons can approach the repair through the vagina, through an abdominal incision, or using minimally invasive techniques like laparoscopy or robotic surgery. A large review of over 1,100 repairs found no significant difference in success rates between vaginal and abdominal approaches: vaginal repairs succeeded about 86.7% of the time on average, and abdominal repairs about 83.8%. One study comparing all three routes found success rates of 92.2% for vaginal, 95.5% for open abdominal, and 89.5% for laparoscopic repair.
Minimally invasive approaches offer some practical advantages. Patients who undergo laparoscopic or robotic repair tend to lose less blood during the procedure and spend fewer days in the hospital. The choice of approach often comes down to surgeon preference and the specific characteristics of the fistula, such as its location and how easily it can be reached.
Overall outcomes are encouraging. A study from a well-resourced surgical center reported an overall anatomical success rate of 95.9% for fistula repair, with 95.5% of first-time repairs succeeding. Even patients who had previously undergone a failed repair had a 96.8% success rate with a second attempt. Recurrence after successful repair is rare, occurring in about 2% of cases, and those recurrences were also successfully treated.
What Recovery Looks Like
After surgical repair, a catheter is left in place for a period of time to keep the bladder empty while the repair site heals. The exact duration depends on the complexity of the fistula, but it commonly ranges from one to three weeks. During this time, you’ll need to manage the catheter at home and keep the area clean to prevent infection.
Physical activity is gradually reintroduced. Walking is generally encouraged early on, but heavy lifting, strenuous exercise, and sexual intercourse are typically restricted for several weeks to avoid putting pressure on the repair. Most people can return to normal daily activities within a few weeks, though full tissue healing takes longer. Follow-up appointments will include an exam to confirm the fistula has closed, and some centers use imaging or repeat dye tests to verify the repair is intact.
The Global Burden of Obstetric Fistula
While surgical fistulas in developed countries are usually repaired quickly, obstetric fistulas in low-resource regions often go untreated for years or even a lifetime. Women living with untreated fistulas face constant urine leakage, skin breakdown, and a high risk of kidney infections. The social consequences are equally devastating: many are abandoned by partners, isolated from their communities, and unable to work.
The condition is directly tied to gaps in maternal healthcare. When women in labor have access to timely cesarean delivery, obstetric fistula is almost entirely preventable. International health organizations consider fistula treatment a priority, but the gap between the number of women who need repair and the surgical capacity available remains vast in many parts of sub-Saharan Africa and South Asia.