An anal fistula can occur after surgery to drain an anal abscess.
In some cases, an anal fistula causes persistent drainage. In other cases, where the outside of the channel opening closes, the result may be recurrent anal abscesses.
The only cure for an anal fistula is surgery.
Anal Fistula may cause the following symptoms:
Pain, which is usually constant, throbbing and worse when sitting down
Skin irritation around the anus, including swelling, redness and tenderness
Discharge of pus or blood
Constipation or pain associated with bowel movements