The fistula threads usually fall off in 7-10 days, and if the tissue cut in the threads is relatively small, the time to fall off is relatively short, within a week. If the fistula is very high or even located in the rectum, it may take 7-10 days or even more than 10 days for the fistula to fall off because there are more tissues ligated in the thread. During this period, if the thread is loose, it is necessary to tighten the thread in time to promote the shedding of the thread, and the treatment of anal fistula is completed only after the incision is completely healed by the shedding of the thread. The patient needs to return to the hospital regularly to check the threads after the fistula surgery, and he or she can pull the threads when washing after defecation to promote their removal.