The purpose of hanging thread after anal fistula surgery is mainly to keep the drainage of the surgical wound smooth and maintain the normal function of the anal sphincter. In most cases, the hanging thread after anal fistula surgery can fall off by itself. Only a few need assistance to fall off. Anal fistula is a granulomatous disease formed after the breakdown of perianal abscess, if you suffer from high complexity of anal fistula, need to use the method of hanging line for treatment, if the hanging line of tissue is less and stronger, usually in about 10 days will fall off on their own. But there are also a few hanging thread more tissue and the strength of the case of looser, in this case will not fall off, need to tighten the line again, increase the strength of the method to make it fall off. Or it can be removed manually. After the operation, we should pay attention to avoid strenuous exercise, try to rest in bed, change the medicine regularly to keep the affected area clean, if there is any discomfort, it is recommended to consult a doctor in time to give treatment.