Anal fistulas do not heal on their own. Untreated, they can recur as perirectal abscesses and therefore must be treated surgically. The principle of treatment is to incise the fistula to create an open wound and induce healing. There are many surgical approaches, and surgery should be selected based on the height of the internal opening and the relationship between the fistula and the anal sphincter. The key to surgery is to minimize damage to the anal sphincter to prevent anal incontinence and to avoid recurrence of the fistula. How is an anal fistula treated? 1, fistulotomy: It is a method to cut open all the fistula and rely on the growth of granulation tissue to make the wound heal. It is suitable for low anal fistula, because the fistula is below the deep part of the external sphincter, after the incision only damage the lower part of the external sphincter skin and shallow, there is no postoperative anal incontinence. 2, hanging thread therapy: is the use of rubber bands or corrosion of the mechanical compression of the drug line, slowly cut open the anal fistula method. This method also has the advantages of simple operation, less bleeding, convenient drug changes, and no skin incision adhesions before the rubber band falls off. 3, anal fistula excision: cut the fistula and remove all the fistula wall to healthy tissue, the wound is not sutured; if the wound is large, it can be partially sutured, partially open, filled with oil gauze, so that the wound grows from bottom to outside until it heals. It is suitable for low level simple anal fistula.