How do you get a perianal fistula?

An anal fistula is defined as an infected tunnel that develops between the skin and the muscular opening at the end of the anus. In most cases, an anal fistula is the result of infections that begin in an anal gland. Rarer forms may communicate with the vagina or other pelvic structures, including the bowel and bladder.

Most fistulas start as Rectoprostatic abscesses. When the abscess opens on its own, or has opened surgically without surgical cleaning of the abscess cavity, a fistula may develop.

Other causes of fistulas are tuberculosis, cancer and inflammatory bowel disease. Fistulas can occur singly or many together.

What are the symptoms of perianal fistula?

Symptoms are usually a purulent drainage of pus and/or itching and discomfort caused to the external tissues by the presence of stool near  the anus. Pain occurs when fistulas become obstructed and abscesses re-form. There may also be bowel flatulence (gas) from the fistula.

To diagnose an anal fistula, medical history taking and physical examination will be conducted by the colorectal specialist. During physical examination, the specialist thoroughly examines the area around the anus, looking for an opening (of the fistula tract) on the skin.