A rectovaginal fistula is an abnormal connection between the rectum and the vagina. This opening allows gas, stool, or discharge to pass from the bowel into the vagina. It’s an uncommon but distressing condition, and childbirth injuries are the most common cause.
How a Rectovaginal Fistula Forms
The rectum and vagina sit very close together, separated by a thin wall of tissue called the rectovaginal septum. When that tissue is damaged by injury, infection, or chronic inflammation, a tunnel-like passage can form between the two. The fistula can be small, allowing only gas to pass through, or large enough for liquid or solid stool to leak into the vagina.
Fistulas are generally classified by their location. Low fistulas sit near the vaginal opening and are often easier to reach surgically. Higher fistulas form deeper in the pelvis and tend to be more complex to repair. The size, location, and underlying cause all influence which treatment approach works best.
Common Causes
Childbirth injuries account for the majority of cases. Prolonged labor, large babies, forceps-assisted delivery, or severe perineal tears can damage the tissue between the rectum and vagina. In some cases, an episiotomy (a surgical cut made during delivery) extends further than intended.
Crohn’s disease is the second major cause. Chronic inflammation from Crohn’s can erode through the bowel wall and into surrounding tissue. About 2.3% of women with Crohn’s disease develop a rectovaginal fistula, according to epidemiological estimates published in the Journal of Crohn’s and Colitis. Ulcerative colitis can also play a role, though less commonly.
Other causes include pelvic or abdominal surgery (such as hysterectomy, prolapse repair, or hemorrhoid removal), where accidental injury or poor healing creates a fistula. Radiation therapy to the pelvic area is another well-known trigger, because radiation causes long-term tissue inflammation that impairs healing. Rarer causes include severe infections, such as abscesses near the anus or infections of the Bartholin glands, as well as fecal impaction and sexual assault.
Recognizable Symptoms
The hallmark symptom is gas passing through the vagina instead of the rectum. Many women also notice liquid stool or fecal material leaking from the vagina, which is both physically uncomfortable and emotionally distressing. The severity typically depends on the size and position of the fistula: a very small one might cause only occasional gas, while a larger one can produce noticeable stool leakage.
A foul-smelling vaginal discharge is common, along with recurrent vaginal infections (vaginitis) that don’t respond well to standard treatment. Some women also experience recurrent urinary tract infections. Pain during intercourse or irritation around the vaginal opening can occur, particularly with low fistulas near the perineum.
These symptoms often cause significant shame and social withdrawal. Many women delay seeking help because they find the symptoms embarrassing to describe, but this is a recognized medical condition with effective treatments.
How It’s Diagnosed
A physical exam is often the first step. Your doctor may be able to see or feel the fistula opening during a vaginal or rectal exam. For fistulas that aren’t immediately visible, a dye test can help: a blue dye is placed in the rectum, and a tampon or gauze is inserted into the vagina. If the tampon picks up the dye, the fistula’s presence is confirmed.
Imaging provides more detail about the fistula’s exact location and the health of surrounding tissue. Ultrasound performed through the rectum or vagina can identify low fistulas effectively. MRI is particularly useful for mapping complex or high fistulas and for evaluating patients with Crohn’s disease, where multiple fistula tracts may be present. These imaging tools help surgeons plan the best repair approach.
Surgical Repair Options
Most rectovaginal fistulas require surgery to close. The specific technique depends on where the fistula sits, what caused it, and whether the surrounding tissue is healthy enough to heal.
The most common approach is a transrectal repair, where the surgeon works through the rectum to create a flap of healthy tissue that covers and seals the fistula opening. This avoids an external incision and works well for many low and mid-level fistulas. A transvaginal approach, where the surgeon works through the vagina, is less commonly performed but offers excellent surgical access and produces similar outcomes. It’s often preferred for patients with active Crohn’s disease affecting the rectum, since operating through inflamed rectal tissue can compromise healing.
A transperineal approach, where the incision is made through the perineum (the area between the vagina and anus), has the advantage of allowing the surgeon to simultaneously repair damaged sphincter muscles. This is particularly relevant for women whose fistula resulted from a birth injury that also weakened their anal sphincter. The trade-off is a larger wound and more surgical trauma.
For high or complex fistulas, an abdominal approach may be necessary, sometimes requiring a temporary colostomy to divert stool away from the repair site while it heals.
Success Rates and Recurrence
Initial surgical repair succeeds about 71% of the time, based on outcomes data published in Cureus. That means roughly 3 in 10 women experience symptom recurrence after their first surgery. The good news is that repeat surgery is highly effective. Among patients whose first repair failed in one study, a second procedure succeeded in nearly all cases.
Success rates vary somewhat by technique. Advancement flap repairs through the vagina succeeded in about 73% of initial attempts, while layered closures through the vagina succeeded in about 67%. Repairs using a Martius flap, which borrows a pad of fatty tissue from the labia to reinforce the closure, succeeded about 71% of the time. These differences are modest enough that the choice of technique usually comes down to the individual anatomy and the surgeon’s expertise rather than one method being clearly superior.
Fistulas caused by Crohn’s disease tend to be harder to treat because the underlying inflammation can undermine healing. Managing the Crohn’s disease itself, often with biologic medications that suppress the immune system’s inflammatory response, is a critical part of treatment. Surgery may be delayed until the disease is better controlled.
What to Expect Before and After Surgery
Before surgery, your doctor will want to make sure any active infection or inflammation has been treated. For Crohn’s-related fistulas, this often means optimizing medications first. Some surgeons place a small silicone thread (called a seton) through the fistula tract weeks before the definitive repair. This keeps the tract open, allows any abscess to drain, and reduces inflammation so the tissue is in better shape for the actual closure.
Recovery after surgery typically involves several weeks of limited activity. You’ll generally be advised to avoid heavy lifting, strenuous exercise, and sexual intercourse while the repair heals. A low-residue diet or stool softeners may be recommended to reduce pressure on the surgical site. Most women can return to normal daily activities within four to six weeks, though complete tissue healing takes longer.
Very small fistulas that cause minimal symptoms, particularly those that develop after childbirth, occasionally heal on their own within the first few months. In these cases, doctors may recommend a period of watchful waiting with dietary adjustments and antibiotics to manage infection before considering surgery.