Fecal matter can exit through the vagina when an abnormal passage forms between the rectum (or colon) and the vaginal canal. This passage is called a rectovaginal fistula, and it allows stool, gas, or foul-smelling discharge to leak into the vagina. The condition is more common than many people realize, and it has several distinct medical causes ranging from childbirth injuries to inflammatory bowel disease. While the topic is understandably distressing, every cause has a recognized treatment pathway, and most fistulas can be repaired.
What Actually Happens Inside the Body
The rectum and the vagina sit right next to each other, separated by a thin wall of tissue called the rectovaginal septum. When that wall is damaged or eroded, the two spaces can become connected by a small tunnel lined with tissue. Stool and intestinal gas follow the path of least resistance, and if that path leads into the vagina, that is where they end up. The fistula itself can be tiny, just a few millimeters across, or large enough to allow solid stool to pass through. The size, location, and cause of the fistula all influence how severe the symptoms are and which treatment makes sense.
What makes these fistulas particularly frustrating for patients and surgeons alike is their tendency to recur after repair. The tissue in the area is often scarred or inflamed, which makes healing unpredictable. Surgeons generally describe rectovaginal fistulas as among the more challenging problems to fix in the pelvis, partly because the anatomy is tight and the blood supply to the septum can be compromised by whatever caused the fistula in the first place.
Symptoms That Bring People to the Doctor
The most alarming symptom is visible stool in the vagina, but many people first notice something subtler. A persistent, foul-smelling vaginal discharge is often the earliest sign, sometimes mistaken for a vaginal infection that does not respond to treatment. Passing gas through the vagina is another common complaint. Some people experience recurrent urinary tract infections or vaginal infections because bacteria from the intestine are being introduced into the vaginal canal.
In one reported case, a 12-year-old girl with Crohn’s disease presented with vaginal passage of stool and gas, which led to the discovery of her fistula.1PubMed Central. Martius flap closure of rectovaginal fistula in a 12-year-old girl with Crohn’s disease In another case, a 40-year-old woman came to the emergency department with foul-smelling vaginal discharge and stool passing through her vagina, which turned out to be caused by a retained foreign body that had eroded through the vaginal wall into the rectum.2JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. Rectovaginal Fistula Complicated by Retained Vaginal Foreign Body: A Case Report The takeaway is that the presentation can range from mild and puzzling to dramatic and unmistakable.
Childbirth Injuries Are the Most Common Cause
Obstetric trauma during vaginal delivery is the leading cause of rectovaginal fistulas worldwide. During labor, the tissue between the rectum and vagina is stretched and compressed, sometimes tearing or being cut (episiotomy). A severe tear that extends into the rectal sphincter or beyond can create a direct connection, or the tissue damage can be subtle enough that the fistula does not become apparent until days or weeks after delivery, once the injured tissue breaks down further.
In a retrospective review at a tertiary referral center, a colorectal surgeon found that 62 patients had birth trauma as the cause of their rectovaginal fistula, underscoring how frequently this occurs in clinical practice.3Japanese Journal of Medical Research. Reconstruction of Perineal Body for Repair of Rectovaginal Fistula Caused by Birth Trauma Offer Best Outcome for Patients – A Colorectal Surgeon’s Experience Many of these injuries involve not just the fistula itself but damage to the perineal body, the block of muscle and connective tissue between the vagina and anus that plays a structural role in continence. Rebuilding this structure is considered essential for a lasting repair.
Not all birth-related fistulas appear immediately. Some women develop them weeks after delivery, after what initially seemed like a normal healing trajectory. This delayed presentation can be confusing and frightening, and it sometimes gets dismissed as normal postpartum changes before the true cause is identified.
Crohn’s Disease and Inflammatory Bowel Disease
Crohn’s disease has a particular tendency to form fistulas. The inflammation in Crohn’s can burrow through the full thickness of the intestinal wall and tunnel into adjacent structures. When that inflammation happens in the rectum, the vagina is right next door. Rectovaginal fistulas are considered the most difficult perianal complication of Crohn’s disease to manage, with a high recurrence rate even after surgical repair.4PubMed Central. Current treatment of rectovaginal fistula in Crohn’s disease
The challenge with Crohn’s-related fistulas is that the underlying disease keeps driving inflammation. You can close a fistula surgically, but if the Crohn’s disease flares again in the same area, a new fistula can form or the old one can reopen. This is why treatment for Crohn’s-related fistulas typically combines medication to control the disease with surgery to close the abnormal passage.5PubMed Central. Rectovaginal Fistula in Crohn’s Disease: When and How to Operate?
One medication that has shown real results is infliximab, a biologic drug that targets the inflammatory molecule TNF-alpha. In the ACCENT II study, about 61% of rectovaginal fistulas in Crohn’s patients closed after an initial course of infliximab infusions. Among those who responded, continued maintenance treatment kept the fistula closed for a median of 46 weeks, compared with 33 weeks on placebo.6Gastroenterology. Long-term treatment of rectovaginal fistulas in Crohn’s disease: Response to infliximab in the ACCENT II Study That is not a permanent cure, but it offers meaningful relief and can sometimes allow a fistula to heal without surgery.
Diverticular Disease
Diverticular disease, the condition where small pouches form in the wall of the colon, is the leading cause of a related but slightly different problem called colovaginal fistula. Here, the abnormal tunnel connects the colon (rather than the rectum specifically) to the vagina.7Diseases of the Colon & Rectum. Diverticular Colovaginal Fistulas: What Factors Contribute to Successful Surgical Management? The mechanism is straightforward: an inflamed or infected diverticulum ruptures and the resulting abscess erodes into the vaginal wall.
This tends to affect older women, particularly those who have had a prior hysterectomy. In one study of 13 patients with genital fistulas caused by diverticular disease, the average age was nearly 69, and every patient with a vaginal fistula had previously undergone a total hysterectomy.8PubMed. Genital fistulas caused by diverticular disease of the sigmoid colon The leading symptom in that group was a malodorous vaginal discharge. Why the hysterectomy connection? Once the uterus is removed, the top of the vagina sits directly against the sigmoid colon with less tissue between them, making fistula formation easier when a diverticulum becomes inflamed.
Cancer and Radiation Therapy
Tumors in the pelvis, whether cervical, rectal, vaginal, or uterine, can invade through tissue walls and create fistulas. A fistula associated with a malignancy of the female reproductive tract can be caused by the tumor itself, by surgery to remove the tumor, or by radiation therapy used to treat it.9PubMed. Fistulas in malignant gynecologic disease: etiology, imaging, and management In practice, radiation-related fistulas are especially tricky because radiation damages the blood supply to surrounding tissues, making the area poorly suited to heal on its own.
Pelvic radiation can cause chronic inflammation in the rectum (radiation proctitis), which over months or years can progress to tissue breakdown and fistula formation. Hyperbaric oxygen therapy has been explored as a treatment for radiation-induced pelvic complications, including fistulas. In one series, two patients with radiation-induced rectovaginal fistulas were treated with hyperbaric oxygen and showed benefit, suggesting it can help improve tissue healing in an area with compromised blood flow.10Journal of Clinical Oncology. The efficacy of hyperbaric oxygen therapy (HBOT) in the treatment of pelvic radiation-induced late side effects
Foreign Bodies and Non-Obstetric Trauma
Objects left in the vagina for extended periods can erode through the vaginal wall and into the rectum. Vaginal pessaries, devices used to support prolapsed pelvic organs, are a well-documented cause when they are left in place too long without follow-up. A neglected pessary can become embedded in the vaginal tissue, and over time the constant pressure erodes through to the rectum.11PubMed. Neglected pessary causing a rectovaginal fistula: a case report In one case, a 66-year-old woman who had a Gellhorn pessary in place for five years developed a fistula when the stem of the device eroded through both the posterior vaginal wall and the anterior rectal wall.12PubMed Central. Staged repair of concomitant rectovaginal fistula and pelvic organ prolapse after removal of a neglected pessary
Other foreign bodies can cause the same problem. The case mentioned earlier of a retained vaginal foreign body leading to an emergency laparotomy and colostomy is a stark example of how serious this can become.2JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. Rectovaginal Fistula Complicated by Retained Vaginal Foreign Body: A Case Report The lesson is simple but important: any device placed in the vagina needs regular monitoring. Pessaries in particular should be removed and cleaned on a schedule, with the vaginal tissue inspected for erosion at each visit.
Congenital Fistulas in Newborns
Some babies are born with an abnormal connection between the rectum and the vagina. This falls under the broader category of anorectal malformations, a group of birth defects affecting how the anus and rectum develop. In the most obvious presentation, the baby has no visible anal opening, and the first clue is meconium (a newborn’s first stool) passing through the vaginal opening.13PubMed Central. Congenital rectovaginal fistula with anorectal agenesis: A rare anorectal malformation
A rarer subtype, called an H-type fistula, is more subtle. In this variant, the baby has a normal-looking anus that functions, but a separate tunnel connects the rectum to the vagina. Because the anus appears normal, the condition can go undiagnosed for months or even years, sometimes only discovered when a child or adolescent reports passing stool through the vagina.14PubMed Central. H-type Rectovestibular Fistula Presenting as a Left Labial Abscess: A Diagnostic Masquerade H-type anorectal malformations are several times more common in girls than in boys, and they can present as the high type (rectovaginal) or the low type (connecting to the vestibule or perineum).15Journal of Pediatric Surgery Case Reports. Congenital H-type recto-vaginal fistula with normal anus: a case report
How the Diagnosis Is Made
If you report stool or gas coming from your vagina, your doctor will likely start with a physical examination that includes both a vaginal and rectal exam. Small fistulas can be surprisingly hard to see or feel, even with direct inspection. When the opening is not obvious, more advanced imaging comes into play.
MRI of the pelvis is currently the gold standard for mapping out a fistula’s exact path, its size, and its relationship to the sphincter muscles. In some cases, an MRI fistulogram using gel instilled into the rectum can highlight the tract and reveal details that a standard MRI might miss.16PubMed. The Essential Role of High-resolution MRI Fistulogram Imaging with Ultrasound Gel Enema in Diagnosing Complex Rectovaginal Fistulas Post-Chemoradiation for Rectal Cancer: A Case Study Review Other tools include endoanal ultrasound, contrast enemas, and examination under anesthesia. The goal of all this imaging is not just confirming the fistula exists but understanding exactly where it sits, because that determines which surgical approach is best.
Surgical Repair Options
Surgery is the definitive treatment for most rectovaginal fistulas. The specific technique depends on where the fistula is located (low, mid, or high in the vagina), how large it is, and what caused it. Surgeons generally wait three to six months before attempting repair so that any active infection can be treated and the tissue around the fistula has time to mature and settle. Operating in inflamed, infected, or acutely injured tissue has a much higher failure rate.
For lower and mid-level fistulas, one well-established technique involves placing a flap of fatty tissue from the vulvar area (called a Martius flap, after the surgeon who first described it in 1928) between the rectum and vagina to provide a fresh layer of well-vascularized tissue. Success rates with this approach range from about 65% to 100% in the published literature, depending on the complexity of the case.17PubMed Central. Surgical Approach for Repair of Rectovaginal Fistula by Modified Martius Flap Other options include advancement flaps, where a layer of rectal tissue is pulled down to cover the internal opening, and for high or complex fistulas, abdominal surgery may be necessary.
One question that comes up frequently is whether a temporary colostomy or ileostomy (diverting stool away from the repair site) is needed. The thinking is that diverting the fecal stream gives the repair a better chance to heal without contamination. However, the data on this is mixed. In a retrospective study of 40 cases, fecal diversion was used in nine patients with complex, high-type fistulas, and six healed while three failed after the stoma was reversed. Statistically, the diversion itself was not a significant predictor of healing success.18International Journal of Surgery Open. Rectovaginal fistulas, outcomes of various surgical repair and predictive factors of healing success. A retrospective cohort study of 40 cases In another French study, direct coloanal anastomosis was strongly associated with successful outcomes for postoperative fistulas, suggesting that the surgical technique itself may matter more than whether stool is diverted.19PubMed Central. Postoperative rectovaginal fistula: stoma may not be necessary-a French retrospective cohort
The Emotional and Social Toll
The physical symptoms of a rectovaginal fistula are bad enough, but the psychological burden deserves its own discussion because it is often underestimated, even by clinicians. The impact on quality of life is described in the literature as profound and disproportionate to the size of the defect. A fistula just a few millimeters wide can upend someone’s social life, work, sleep, and intimate relationships.20PubMed Central. A comprehensive review of iatrogenic rectovaginal fistula after rectal cancer surgery
The unpredictability of leakage generates constant anxiety. Many women report avoiding travel, social events, and even going to work because they cannot predict when an episode of discharge or soiling will occur. The demanding hygiene measures required to manage the symptoms take up time and mental energy. Sexual dysfunction is one of the most debilitating consequences: pain during intercourse, fear of vaginal soiling, and altered body image lead many women to stop being intimate entirely, even when they still have a partner and desire for connection.
A qualitative study exploring women’s lived experiences with rectovaginal fistulas identified themes of humiliation, secrecy, fear, sleep disturbance, isolation, and what the researchers described as a mental crisis.21PubMed Central. Women’s experiences of rectovaginal fistula: an ethno- religious experience In some cultural and religious contexts, women with fistulas face stigma related to being considered ritually “unclean,” adding a layer of social exclusion on top of the physical suffering. The shame associated with fecal incontinence in any form makes many women reluctant to seek help, sometimes for years.
When to Seek Medical Attention
Any persistent vaginal discharge that smells fecal, any passage of gas from the vagina that you cannot explain by recent sexual activity or normal anatomy, and certainly any visible stool in the vagina warrants a visit to a doctor. These symptoms do not resolve on their own, and early evaluation can prevent complications like worsening infection or enlargement of the fistula tract. The right specialist is typically a colorectal surgeon or a urogynecologist, though your primary care doctor or gynecologist can start the evaluation and refer you.
If you have Crohn’s disease and notice new vaginal symptoms, bring them up at your next gastroenterology visit even if you feel embarrassed. Crohn’s-related fistulas are best managed when caught early, before the tract becomes large or the surrounding tissue becomes heavily scarred. Similarly, if you have a vaginal pessary in place, attend your scheduled follow-up appointments for cleaning and inspection. The erosion that leads to fistula formation is slow and painless in the early stages, which is exactly why it gets missed when follow-up lapses.
Pessary Care and Fistula Prevention
Pessaries are useful devices for managing pelvic organ prolapse without surgery, but they require consistent maintenance. Most guidelines recommend removal and cleaning every three to six months, with inspection of the vaginal walls at each visit. Women who are able to remove and reinsert their pessary at home (self-care pessary management) may have an advantage in catching early signs of erosion. If you notice new vaginal discharge, bleeding, or discomfort with a pessary in place, do not wait for your next scheduled appointment.
The five-year neglected pessary case described earlier is an extreme example, but shorter periods of neglect can also cause harm.12PubMed Central. Staged repair of concomitant rectovaginal fistula and pelvic organ prolapse after removal of a neglected pessary Older women, those with limited mobility, and those without reliable access to gynecologic follow-up are at highest risk for pessary-related complications. If regular office visits are not feasible, the tradeoff between pessary use and surgical correction of prolapse should be discussed openly with a provider.