Anal fistula is a common condition in a gland in the anus gets infected and the infection pushes sideways from the anal canal to the skin around the bottom, often about 2-3cm from the anus itself. An infection or abscess in the skin around the anus is often the first awareness that a patient has of having a fistula. An abscess may spontaneously discharge pus but at other times may require surgical drainage under a general anaesthetic.
Treating anal fistulas can be simple but may be difficult and require several operations. The main difficulty is to treat the infection and the fistula without damaging the sphincter muscle which is responsible for continence (bowel control).
There are a range of procedures for treatment for anal fistula including lay open (cutting out of fistula), insertion of a Seton (like a piece of fishing line lying within the fistula track and tied in a knot on the outside) to keep the infection under control and use of other procedures including gluing the fistula, inserting a plug into it or closing it with healthy tissue brought in from bringing healthy tissue to occlude to opening of the fistula (a flap). The choice of procedure will depend on the relationship of the fistula and infection to the sphincter muscle.