1, the classification of anal fistula (1) low simple anal fistula: there is only one tube and through the external sphincter below the deep layer, the internal mouth is located in the anal sinus. (2) high simple anal fistula: there is only one tube, the pathway is above the deep layer of the external sphincter, and the internal mouth is located in the anal sinus. (3) Low complex anal fistula: the canal is below the deep layer of the external sphincter, but there are 2 or more external ports and canals, and the internal port is in the anal sinus area (including multiple fistulas). (4) High complex anal fistula: there are more than 2 ducts or their supervisors passing above the deep layer of the external sphincter, and there are 1 or 2 or more internal ports. 2, anal fistula efficacy standards (1) healed: symptoms disappear, anal fistula healing. (2) Ineffective: anal fistula is not healed after treatment. (3) Long-term efficacy criteria: no recurrence of the fistula at the original site after 2 to 3 years of follow-up is considered as long-term cure. (1) Pain, fever and urination disorder are the same as those for hemorrhoids. (2) Sequelae: (1) Incomplete anal incontinence: partial damage to the muscles that maintain the anal sphincter function, and uncontrollable gas and loose stool at ordinary times or during defecation. (2) Complete anal incontinence: the main muscles that maintain anal function are severed, and dry and loose stools and gas cannot be controlled on their own.