Fistula

Causes
An anal fistula is usually caused by an anal abscess, an infection-filled cavity occurring in the underlying tissues of the anal canal. When an abscess bursts or is opened, and the pus or fluid drains from it, an anal fistula is often formed. It then remains open, even after the abscess has healed.

If you have an inflammatory bowel disease (IBD)—such as diverticulitis, colitis or Crohn’s—you are more likely to develop an anal abscess and fistula. Individuals with diseases that reduce the body’s immunity—such as AIDS or cancer—are also at higher risk.

Symptoms
Ongoing pain, swelling and tenderness are symptoms of both anal abscess and fistulas. You may also experience drainage of pus and fluid from the abscess, which can cause irritation and itching of the skin around the anus. Other symptoms include fever, chills, fatigue or weakness.

Diagnosis
Your surgeon may be able to diagnose an anal fistula by physically examining the area surrounding the anus. However, if external signs are missing, then an internal exam will be necessary. An instrument called an anoscope is used to inspect the anal canal and rectum for indications of an abscess or other inflammation.

View our patient guide for illustrations and more detailed information. You can also visit our resource library for surgeons. Please note this information has been created for medical professionals and may not be appropriate for everyone.

Causes
Most rectovaginal fistulas result from an injury to the perineum (the area of tissue between the vagina and the rectum) during childbirth. However, they can also be caused by radiation treatment, inflammatory bowel disease or vaginal surgeries, rectal surgeries or trauma.

Symptoms
The most common symptom of a rectovaginal fistula is passage of bowel contents (gas and/or stool) through the vagina. You may also experience inflammation of the vagina, which results in burning, itching and discharge; or inflammation of the bladder, which causes frequent and sometimes painful urination.

Diagnosis
To diagnose a rectovaginal fistula, the surgeon usually performs a physical examination of the rectum and vagina. This is often followed by an endoscopic examination of the rectum and the lower part of the colon using a thin, flexible tube with a light and a camera lens.

View our patient guide for illustrations and more detailed information. You can also visit our resource library for surgeons. Please note this information has been created for medical professionals and may not be appropriate for everyone.