It usually takes about 7-10 days for the post-operative surgical hanging threads to come off. Nowadays, the material used for hanging the threads is elastic rubber bands. How long it takes to come off depends on the thickness of the rubber band and the amount of tissue hanging under it. The hanging wire is often used for high complex anal fistulas because the internal opening is relatively high and the muscles and anal sphincter connected to the fistula are thicker, so if this piece of tissue is completely cut off, there is a risk of anal incontinence. Therefore, a rubber band is used to slowly cut the tissue, cutting it while giving time for the local tissue to adhere and for the local tissue to grow. The rubber band comes off and a part of the muscle grows on the back side, which will not lead to a sudden rupture of the anal sphincter and lead to anal incontinence.