It takes about 3 weeks for the incision to heal completely after the fistula wire comes off. Most of the fistulas that require wire hanging are high anal fistulas, so the incision is deep and traumatic. The thread is used to cut the internal opening by using the elastic cutting function of the rubber band, so that the fistula can be completely healed. The threads usually fall off about 7-10 days after surgery, and only after they fall off can the internal opening heal again so that the incision can heal slowly. Patients also need to return to the hospital regularly after surgery for follow-ups and drug changes to understand the healing of the incision and to clarify the growth of the granulation, which can prevent post-operative pseudo-healing that can lead to anal fistula recurrence.