The fistula surgery hanging thread will be tightened a week or so after the surgery, the fistula surgery hanging thread is to use the elasticity of the rubber band to gradually cut this part of the sphincter, so that the sphincter gradually necrosis, is a slow process, will not suddenly cut off the sphincter and lead to anal incontinence. After a week or so, a part of the sphincter under the rubber band has necrosis, the sphincter strangled under the rubber band is not so much, so the rubber band is relatively loose, can not play a cutting role, will tighten the rubber band in local anesthesia, knot, let the rubber band tighten up again, the use of elasticity to cut the remaining sphincter, will be a bit painful, but not particularly painful, because will inject anesthetic.