When an irregular false tract occurs between the inside of the rectum and the outside skin surface, an Anal Fistula forms. The anal fistula is classified according to the condition of the tract and the relation of the internal opening to the anal sphincter muscle. Most commonly, this condition develops because of an anal abscess that went untreated. The anal abscess itself is usually the result of a small gland that becomes infected.

The most common symptoms are pain, recurrent swelling, pus discharge and discomfort during the discharge of stool. The most common treatment in India is a surgical treatment; the most common method is the minimally invasive Video Assisted Anal Fistula Treatment.