An anal fistula is an abnormal tunnel between the anal canal and the outer skin of the anus.
An anal fistula usually results from a previous infection (abscess) of the anus or rectum. After an abscess has been drained, a tunnel may persist connecting the anal gland from which the abscess arose to the skin. Inflammatory diseases of the anorectal area, such as Crohn’s disease, can predispose a person to the development of anal fistulas, but again, most fistula patients do not have an underlying illness.
Surgery is always required to cure an anal fistula. Some patients do take antibiotics to reduce inflammation, but this will not cure the problem. The procedure is called a fistulotomy and involves opening the tunnel. This coverts the tunnel into a groove which will then heal from the inside out. Most fistulas must be treated in the operating room under general anesthesia. It is almost always a short outpatient procedure. If the fistula is complex and goes through a lot of anal sphincter muscles, more complicated techniques may be necessary. After the surgery, a period of rest and recovery is required. Medications to soften bowel movements and pain medication are prescribed. Bowel movements do not affect healing. Warm soaks to clean the anal area and provide pain relief are also recommended. Most patients are back to regular activities within a few days.