It is a small tunnel that develops from the inner lining of the end of the large bowel (rectum and anus), toward the surrounding skin around the anus. It is usually caused by an infection near the anus, which results in a collection of pus (abscess) in the nearby tissue. When the pus drains away, it can leave a small channel behind. Anal fistulas cause unpleasant symptoms, such as persistent discharge, discomfort, and skin irritation. Surgery is often needed to treat anal fistulas as they do not usually heal by themselves. There are several different procedures for anal fistula. The best option for you will depend on the position of the fistula and whether it’s a single channel or branches off in different directions.
– Fistulotomy: involves cutting along the whole length of the fistula to open it up, so it heals as a flat scar. It is the most effective treatment for many anal fistulas. But it's usually only suitable for fistulas that do not pass through much of the sphincter muscles. This is because the risk of incontinence is lowest in these cases.
– Seton insertion: A seton is a piece of surgical thread that's left in the fistula for several
weeks/months to keep it open. This allows it to drain and helps it heal, while avoiding the need to cut the sphincter muscles. If your fistula passes through a significant portion of anal sphincter muscle, a seton would be initially recommended. Loose setons allow fistulas to drain, but do not cure them. To cure a fistula, tighter setons may be used to cut through the fistula slowly, which require several procedures. Or carrying out several fistulotomy procedures, carefully opening up a small section of the fistula each time, or a different treatment.
– Other procedures include Advancement flap procedure, Ligation of the intersphincteric fistula tract
(LIFT) procedure, Endoscopic ablation, and Laser surgery. One of these procedures can be carefully selected to treat your anal fistula when indicated.