The presence of stool in the vagina is an abnormal but recognized medical issue that requires prompt professional attention. If you are experiencing symptoms related to this condition, consult a healthcare provider, such as a gynecologist or a colorectal surgeon, for an accurate diagnosis and treatment plan.
Defining the Abnormal Connection
The passage of fecal material into the vagina is caused by an abnormal tunnel-like connection called a rectovaginal fistula. A fistula is a passageway that develops between two organs or vessels that do not typically connect. The rectum and the vagina are normally separated by the rectovaginal septum, which acts as a natural barrier.
When a fistula forms, it bypasses this protective septum, creating an opening that allows contents from the rectum, including gas and stool, to leak into the vaginal canal.
The severity of the condition depends on the fistula’s size, location, and underlying cause. Fistulas are classified by position: low fistulas are near the perineum and anus, while high fistulas are situated higher up near the posterior vaginal fornix. Size can range from small pinholes to large openings exceeding 2.5 centimeters.
Common Reasons This Occurs
The most frequent cause of a rectovaginal fistula is injury sustained during childbirth, often called an obstetric fistula. This accounts for the majority of traumatic cases. Complications from vaginal delivery, such as third- or fourth-degree perineal lacerations, are the primary event. These tears extend into the anal sphincter muscles or rectal lining and can lead to fistula formation due to infection or poor healing. Difficult or prolonged labor and the use of instruments like forceps increase the likelihood of this trauma.
A major cause is the chronic inflammatory condition, Crohn’s disease, a type of inflammatory bowel disease (IBD). Crohn’s disease causes inflammation affecting the entire thickness of the intestinal wall, allowing ulcers to penetrate and create a tunnel to the vagina. Fistulas in these patients often present a greater challenge for healing due to the underlying inflammatory process.
Fistulas can also arise as a complication of prior pelvic or abdominal surgeries. Procedures such as hysterectomies or rectocele repairs carry a risk of iatrogenic injury, where the tissue between the rectum and vagina is unintentionally damaged. Tissue damage following radiation therapy for pelvic cancers, such as cervical or rectal cancer, is another recognized cause. Radiation can cause chronic inflammation and poor blood supply, potentially resulting in tissue necrosis and fistula formation months or years after treatment.
Physical Signs and Related Symptoms
The most definitive sign of a rectovaginal fistula is the passage of gas or stool through the vagina. This leakage can range from liquid stool to small solid pieces, depending on the fistula’s size, and may be constant or intermittent. It is often accompanied by a foul-smelling vaginal discharge, which occurs as fecal matter and bacteria mix with normal vaginal secretions.
The introduction of intestinal bacteria frequently leads to recurrent vaginal or urinary tract infections. Patients may also experience persistent irritation, inflammation, and pain in the perineal region. Depending on the tissue damage, some individuals may also experience difficulty controlling bowel movements, known as fecal incontinence.
These symptoms cause physical discomfort, emotional distress, and potential issues with intimacy. Small fistulas might only cause chronic discharge, while larger ones result in the obvious passage of solid material.
Medical Diagnosis and Repair
A healthcare provider begins the diagnostic process with a detailed medical history and a physical examination of the perineum and vagina. The physical exam includes a speculum examination to visually identify the opening in the vaginal wall and a digital rectal exam to feel for a tract. If the opening is not immediately visible, a dye test may be performed, where a dye is instilled into the rectum, and a tampon is placed in the vagina to check for staining.
Imaging and Visualization
Various imaging techniques are used to confirm the diagnosis, determine the size, and map the tract’s course. Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans provide detailed images of the pelvic structures, helping to identify the fistula and any associated abscesses or inflammation. Endoscopy, such as a sigmoidoscopy or colonoscopy, allows for internal visualization of the rectal lining to assess the tissue condition and rule out underlying conditions like cancer or active inflammatory bowel disease.
Treatment Approaches
Treatment for a rectovaginal fistula is most often surgical, although the approach varies based on the fistula’s complexity, cause, and the patient’s overall health. Simple, small fistulas may occasionally close with conservative management, which involves dietary changes, antibiotics to clear infection, and bowel rest. Most cases, however, require an operation to achieve definitive closure.
Before surgical repair, any surrounding infection or inflammation must be fully resolved, which may involve antibiotics or the placement of a draining seton—a string placed through the tract to promote drainage. The primary surgical goal is to remove the diseased tissue lining the tract and close the openings in both the rectum and the vagina with multiple layers of healthy tissue. Depending on the location, the surgeon may use a transvaginal approach for low fistulas or a transabdominal approach for high fistulas. In complex cases, especially those involving poor tissue quality from radiation or Crohn’s disease, the surgeon may use a tissue graft, such as a flap of muscle, to separate the two suture lines and reduce the risk of recurrence. In certain severe cases, a temporary diverting stoma may be created to reroute the stool away from the repair site, allowing for optimal healing before a second procedure closes the stoma.