You can determine the high and low levels of anal fistula based on the relationship between the fistula and the deeper part of the external anal sphincter. Anal fistula is one of the common rectal-anal tube diseases, mostly caused by sinusitis, anal fissure, perineal surgery and other infections, mainly manifested as perianal pus, swelling and pain, itching and other symptoms. 1. low anal fistula: low anal fistula refers to the fistula in the deep outer sphincter, can be divided into low simple anal fistula and low complex anal fistula. 2. high anal fistula: high anal fistula belongs to the external sphincter deep layer above the fistula. Can be divided into high simple anal fistula and high complex anal fistula. The treatment of anal fistula is mainly based on anti-inflammatory sterilization, you can follow the doctor’s instructions to use antibiotics for treatment, commonly used drugs are cefixime, amoxicillin, metronidazole and so on. Different positions of the anal fistula using different surgical methods, such as fistulotomy, anal fistula resection, hanging wire surgery. Pay attention to the observation of the wound, avoid scratching, keep the perianal area clean and hygienic, wear cotton underwear and change frequently, disinfect and change the medicine regularly. If the patient has any discomfort after the operation, please go to the regular hospital in time to give targeted treatment, to avoid delaying the condition.