A bladder fistula is an abnormal opening between the bladder and a neighboring organ or the skin, allowing urine to leak through a pathway that should not exist. These connections can form between the bladder and the vagina, the bowel, the uterus, or even the body’s surface, and the specific type determines which symptoms appear and how the problem is treated. Bladder fistulas are caused by childbirth injuries, surgery, bowel disease, radiation, and occasionally trauma, and while most require surgical repair, the success rates for that surgery are generally high.
How a Bladder Fistula Forms
The bladder sits in the pelvis surrounded by other organs separated from it by layers of tissue. When those separating layers are damaged, the body’s healing process can go wrong. Instead of sealing the wound normally, the damaged tissue forms a tunnel lined with epithelial cells, and once that lining is established, the tunnel tends to stay open rather than close on its own. Over time the fistula tract becomes epithelialized, which prevents spontaneous healing and is the main reason most fistulas require intervention rather than just waiting.1PubMed. Spontaneous closure of vesicovaginal fistulas after bladder drainage alone: review of the evidence
Fistulas of the urinary tract can involve the upper tract (kidney or ureter), the lower tract (bladder or urethra), or the female reproductive tract (vagina or uterus), and the causes range from infection and inflammatory disease to cancer, congenital conditions, trauma, and surgical injury.2PubMed. Fistulas of the genitourinary tract: a radiologic review The most common bladder fistulas, by far, are those connecting the bladder to the vagina (vesicovaginal fistulas) and those connecting the bladder to the colon or sigmoid (colovesical fistulas). Each has a distinct set of typical causes.
Causes of Bladder Fistulas
Childbirth Injury
In much of the world, the most devastating cause of bladder fistulas is prolonged obstructed labor. When a baby cannot pass through the birth canal and delivery is delayed for hours or days, the trapped baby’s head compresses the tissue between the bladder and the vagina, cutting off blood supply. That tissue dies, and when it sloughs away after delivery, it leaves a hole between the bladder and the vagina through which urine leaks continuously.3PubMed Central. Overcoming phase 1 delays: the critical component of obstetric fistula prevention programs in resource-poor countries This complication is rare where cesarean sections are readily available, but in low-resource settings it remains common.4PubMed. Obstetric vesicovaginal fistula as an international public-health problem
Pelvic Surgery
In higher-income countries, the most frequent cause of vesicovaginal fistula is iatrogenic injury during pelvic surgery, particularly hysterectomy. Accidental damage to the urinary tract or bowel during the operation, or postoperative infection that erodes tissue, can create a fistula in the weeks following surgery.5PubMed. Risk of pelvic organ fistula in patients undergoing hysterectomy Other surgical causes include radiation therapy and infection.6PubMed Central. Vesicovaginal Fistulas: Prevalence, Impact, and Management Challenges
Not all hysterectomy approaches carry the same risk. A large study found that an abdominal approach carried a higher chance of genitourinary injury compared with a vaginal or laparoscopic approach. Additional risk factors included having a concurrent prolapse repair, a diagnosis of endometriosis, and undergoing surgery at a hospital that performs fewer hysterectomies.7Obstetrics & Gynecology. Urologic Injury and Fistula After Hysterectomy for Benign Indications
Bowel Disease
A colovesical fistula connects the colon (usually the sigmoid) to the bladder. Diverticular disease is the leading cause. When a diverticulum becomes inflamed and the infection erodes through the wall of the bowel into the adjacent bladder, a channel forms between the two organs.8PubMed Central. Colovesical Fistula due to Sigmoid Diverticulitis Crohn’s disease, colorectal cancer, and other inflammatory conditions can produce the same result.
Radiation and Cancer
Radiation therapy for pelvic cancers (cervical, rectal, bladder, or prostate) can damage tissue slowly over months or years. The radiation causes fibrosis and poor blood supply in the bladder wall, and that weakened tissue can eventually break down into a fistula. These radiation-induced fistulas are among the most difficult to repair because the surrounding tissue is scarred and has limited blood flow, which makes healing unpredictable and recurrence more likely.9American Journal of Case Reports. Radiotherapy-Related Bladder Fistula: A Hidden Cause of Recurrent Abdominal Symptoms
Trauma and Rare Causes
Pelvic fractures from accidents can injure the bladder and create a fistula to the skin surface, called a vesicocutaneous fistula. In one reported case, a woman treated conservatively for a pelvic fracture developed swelling in her thigh weeks later, which turned out to be urine draining through a fistula tract from her bladder.10PubMed Central. Urine in the thigh, an extraordinary complication of pelvic fracture: Vesicocutaneous fistula Congenital bladder fistulas also exist but are extremely rare. One published case involved a congenital vesicovaginal fistula that went undiagnosed until the patient was sixteen, despite extensive investigation throughout childhood.11Elsevier / PubMed Central. Congenital vesicovaginal fistula in association with hypoplastic kidney and uterus didelphys
Symptoms and How They Differ by Type
The hallmark symptom of a vesicovaginal fistula is continuous, uncontrollable leakage of urine from the vagina. It is not like stress incontinence, which happens with coughing or laughing. The leakage is constant, soaking clothing and bedding around the clock. This can also cause recurrent vaginal and urinary tract infections, skin irritation, and a persistent odor that is difficult to manage.
Colovesical fistulas produce a very different symptom pattern. The telltale signs are pneumaturia (air bubbles in the urine) and fecaluria (fecal material in the urine), along with frequent urinary tract infections that keep coming back despite antibiotic treatment.8PubMed Central. Colovesical Fistula due to Sigmoid Diverticulitis If you notice cloudy or foul-smelling urine with what looks like debris, or if you pass gas while urinating, these are strong indicators of a bowel-to-bladder connection.
Fistulas involving the skin (vesicocutaneous) present as persistent wound drainage that, on testing, turns out to be urine. The onset can be delayed by weeks after the original injury, which sometimes makes the diagnosis difficult.
Getting a Diagnosis
Diagnosing a bladder fistula often starts with clinical suspicion based on the symptoms. For vesicovaginal fistulas, a dye test is commonly used: blue dye is instilled into the bladder through a catheter, and if a tampon or pad placed in the vagina turns blue, the fistula is confirmed. The challenge is pinpointing the exact location and size, which matters for planning surgery.
CT scanning is the most useful imaging tool, particularly for colovesical and enterovesical fistulas. It has a diagnostic accuracy that ranges from about 60% to 100% depending on the fistula’s characteristics. Cystoscopy, which involves looking inside the bladder with a camera, misses more than half of fistulas. It may show swelling, mucus, or stool inside the bladder that hints at a fistula tract without actually revealing the opening itself.12PubMed Central. Four cases of enterovesical fistula and the importance of CT in the diagnosis Contrast-enhanced CT, where dye is injected so it highlights the fistula tract, improves the detection rate.
Treatment Options
A small number of vesicovaginal fistulas close on their own if they are very small, recently formed, and the bladder is kept continuously drained with a catheter for several weeks. But the window for this conservative approach is narrow, and most fistulas have already begun to epithelialize by the time they are diagnosed. Once that lining is established, surgery is the only realistic path to closure.
Surgical Repair of Vesicovaginal Fistulas
There are three main surgical approaches for vesicovaginal fistula repair: transvaginal (through the vagina), transabdominal (through an incision in the abdomen), and minimally invasive (laparoscopic or robotic). The transvaginal route is used most frequently and tends to have the shortest operating time, the least blood loss, and the briefest hospital stay. One study found the transvaginal approach had an operative time averaging about an hour compared to nearly three hours for minimally invasive approaches.13PubMed Central. Vesicovaginal Fistula Repair by Transvaginal Route: Comparison of Resource Utilisation and Outcome with Literature Reported Population Matched Cohort of Patients Operated by Minimally Invasive Route
Success rates across all approaches are high. Vaginal repair achieves anatomical closure in about 91% of first attempts, and abdominal repair in about 86%, with nearly all patients reaching full closure after a second procedure when needed.14PubMed Central. The cost effectiveness of vaginal versus abdominal repair of vesicovaginal fistulae The abdominal approach, while effective, comes with a longer hospital stay (a median of about three days versus one day for vaginal or laparoscopic repair), a higher rate of major complications, and more need for blood transfusion.15Urogynecology. Perioperative Outcomes of Vesicovaginal Fistula Repair by Surgical Approach
The choice of approach depends on the fistula’s location, size, and complexity. High fistulas near the top of the vagina may be difficult to reach vaginally and are better suited to an abdominal or robotic approach. Simple, low fistulas are ideal for vaginal repair.
Robotic and Laparoscopic Repair
Minimally invasive techniques have been gaining ground, particularly for fistulas that would otherwise require open abdominal surgery. A systematic review found that laparoscopic repair achieves cure rates between 80% and 100%, with the extravesical technique performing similarly to the traditional transvesical approach.16PubMed. Laparoscopic and Robotic-assisted Vesicovaginal Fistula Repair: A Systematic Review of the Literature Robotic-assisted repair has shown success rates above 93%, even in complex cases that included prior failed repairs and radiation-damaged tissue.17PubMed. Robot-assisted Repair of Complex Vesicovaginal Fistulae: Feasibility and Outcomes Another series of 30 patients treated robotically, more than a third of whom had complex fistulas, reported no recurrence in about 93% of cases with a median follow-up of about nine months.18PubMed. Robot-assisted vesicovaginal fistula repair: a safe and feasible technique
Tissue Flaps
When a fistula is recurrent, very large, or surrounded by unhealthy tissue from radiation or infection, surgeons often place a layer of healthy tissue between the repaired bladder and the adjacent organ. These interpositional tissue flaps bring fresh blood supply to the repair site, improving healing.19PubMed. The Use of Tissue Flaps in the Management of Urinary Tract Fistulas The Martius flap, harvested from the fat pad of the labia, is one of the most commonly used. Studies report better success rates and fewer complications, including less incontinence and less sexual pain, when a Martius flap is used for vaginal and urethral fistula repairs, and its use is particularly recommended for recurrent or multiple fistulas.20PubMed. Role of the martius procedure in the management of urinary-vaginal fistulas
Surgery for Colovesical Fistulas
When the fistula connects bowel to bladder, the treatment is usually surgical and involves removing the diseased segment of colon, closing the bladder defect, and reconnecting the remaining bowel. About three quarters of cases can be managed in a single operation.21PubMed Central. Indications and outcomes of enterovesical and colovesical fistulas: systematic review of the literature and meta-analysis of prevalence More complicated cases, such as those with abscess, severe inflammation, or bowel obstruction, may need a staged approach with a temporary colostomy bag before the final reconnection.22PubMed. Surgical protocol and outcome for sigmoidovesical fistula secondary to diverticular disease of the left colon: A retrospective cohort study
What Makes a Fistula Come Back
Despite high overall success rates, some fistulas do recur after repair. A systematic review identified the strongest predictors of recurrence: fistulas larger than two to three centimeters, severe scarring around the fistula, involvement of the urethra or bladder neck, and having more than one fistula. The odds of recurrence were dramatically higher with severe fibrosis (odds ratios as high as 12) and with multiple fistulas (odds ratios of 4 to 8).23PubMed Central. Predictors of recurrence after vesicovaginal fistula repair: a systematic review of surgical and patient-related factors Having an active urinary tract infection at the time of repair and obstetric causes (as opposed to surgical causes) also raised the recurrence risk.24PubMed. Prognostic factors of recurrence after vesicovaginal fistula repair
On the protective side, early intervention, surgery at a specialized center, and the use of tissue flaps all reduced the chance of recurrence.23PubMed Central. Predictors of recurrence after vesicovaginal fistula repair: a systematic review of surgical and patient-related factors This is part of why fistula repair programs in low-resource settings emphasize training dedicated fistula surgeons rather than having general surgeons attempt repairs occasionally.
Recovery After Surgery
Postoperative care for bladder fistula repair revolves around keeping the bladder empty while the repair heals. A catheter is left in place for a period that varies widely by surgeon and setting, typically ranging from about two to four weeks.25BMC Pregnancy and Childbirth. Clinical procedures and practices used in the perioperative treatment of female genital fistula during a prospective cohort study During this time you should expect to avoid strenuous activity and sexual intercourse. Surgeons generally advise waiting at least three months before resuming intercourse, and sometimes longer if the repair was complex.
For colovesical fistula surgery, recovery resembles any major bowel operation. You may be on a liquid diet initially, progressing to solid food as bowel function returns. If a temporary colostomy was created, a second surgery to reverse it is usually scheduled several months later once the repair site has fully healed.
The Emotional and Social Toll
The physical symptoms of a bladder fistula, especially continuous urine leakage, ripple into every part of a person’s life. In low-income settings where obstetric fistula is common, the consequences extend far beyond the medical. Women living with fistula in Nigeria, for instance, were found to be abandoned by family and friends, stigmatized, and discriminated against, leading to depression, loneliness, and a severe loss of self-worth.26PubMed Central. The psycho-social impact of obstetric fistula and available support for women residing in Nigeria: a systematic review
Surgical repair does improve psychological outcomes, but the improvement tracks closely with physical results. In a study that followed women after fistula repair, those who reported being fully cured showed large drops in depression and PTSD symptoms. But women who continued to experience any leakage after surgery endorsed significantly higher rates of psychological distress, and the severity of residual leaking was strongly correlated with depression, PTSD, and somatic symptoms.27PubMed Central. Psychological Symptoms and Social Functioning Following Repair of Obstetric Fistula in a Low-Income Setting This finding underscores why achieving a complete, leak-free repair matters so much, and why follow-up care needs to address mental health alongside physical healing.
The Global Treatment Gap
Obstetric fistula has been virtually eliminated in wealthy countries through universal access to emergency obstetric care. But in parts of sub-Saharan Africa and South Asia, hundreds of thousands of women live with unrepaired fistulas, many of them for years or decades. Over the last two decades, the UNFPA-led Campaign to End Fistula and organizations including FIGO and the Fistula Foundation have worked to close this treatment gap.28BMJ. Global, regional and national estimates of obstetric fistula prevalence FIGO’s Fistula Surgery Training Initiative, launched in 2012, has trained fellows from 22 affected countries who have collectively performed over 10,000 repairs.29PubMed Central. Addressing the fistula treatment gap and rising to the 2030 challenge
The challenge is not only surgical capacity. Women in remote areas may not know that treatment exists, may lack transportation to a surgical center, or may face social barriers that prevent them from seeking care. Prevention through improved access to skilled birth attendants and cesarean sections remains the most effective strategy, but for the women already living with fistulas, expanding access to surgical repair and reintegration support is an ongoing global health priority.