Understanding Common Causes of Anal Fistula

An anal fistula is a terrible and painful thing to discuss, but the first step toward being in a position to get the right treatment is knowing how this happens. The abnormal tunnel that forms between the skin around the anus and the anal canal that occurs as a reaction to infection that causes the body to form a small channel so pus can drain is an anal fistula.

The most common solitary cause of an anal fistula is an anal abscess. A fistula will form in about 50% of patients with abscesses. The abscesses first develop from infected anal glands, which are supposed to secrete mucus to assist in bowel function. If the glands are blocked or become infected, an abscess will develop with pus. As this abscess tries to drain, it will severs – the fistula – from the inside of the anal canal to the outside skin.

Crohn’s disease is also a leading cause of how anal fistulas form. This bowel disease condition of chronic inflammation of the entire gastrointestinal tract, including the anal canal, leads to about 25-30% of Crohn’s patients ultimately developing an anal fistula. The chronic inflammation of the walls of the intestines is what makes them vulnerable to forming abnormal connections like fistulas.

Trauma to the area of the anus can, infrequently, result in fistulas. This may be the result of surgical procedures within the area, perinatal trauma, or other trauma within the area. When there is injury to the tissues, healing will be incomplete on some occasions and result in an anal fistula as the body will attempt to create drainage tracts.

Radiation given to treat pelvic cancer occasionally produces anal fistulas. The normal tissue as well as the cancer cells can be destroyed by the radiation, impairing the structure and making the area vulnerable to the development of a fistula, even several years after finishing treatment.

Tuberculosis, while rare in developed countries, can result in anal fistulas when the disease infects the intestinal system. The chronic inflammation and tissue destruction caused by TB can develop fistulas.

Certain sexually transmitted illnesses, more notably those that cause inflammation and ulcers on the anal region, may cause an increased risk of having an anal fistula. Tissue damage through these infections is risk factor for fistula development.

Cancer of the rectum or anus will occasionally present with or result in anal fistulas. The abnormal growth of tissues may erode through normal barriers, creating abnormal passages.

Certain unexplained congenital anomalies that can be seen at birth can also predispose them to the development of anal fistulas in life. These would generally be associated with abnormal anorectal embryogenesis.

Anal fistula formation can also be caused by poor hygiene, which allows bacteria to grow in the anal canal, raising the risk of infection. Nevertheless, it should be remembered that most individuals with good hygiene develop anal fistulas for other reasons.

Chronic constipation or diarrhea puts a strain on the anal tissue, which can cause gland obstruction or infection leading to fistulas. Straining due to constipation or irritation due to diarrhea can tear the thin lining of the anus.

Understanding the etiology helps the medical professionals prescribe the most suitable treatment for an anal fistula. The treatment is usually surgical removal of the fistula tract with the aim of preserving anal sphincter function. The procedure depends on the site, complexity, and etiology of the fistula.

If you suspect you have an anal fistula, which is typically a chronic pain, swelling, and drainage around the anus, visit your doctor early. Early treatment tends to be more effective and prevents complications.