The clinical symptoms of anal fistula are mainly manifested as intermittent discharge of secretion from the local external opening near the anus, accompanied by varying degrees of pain in the anal area, and occasionally, pus is expelled with the stool. The main reason for its formation is that the anal fistula not only has an external opening, but also an internal opening near the dentate line of the anal canal. The internal opening discharges pus intermittently due to the stimulation of local inflammation. The composition of an anal fistula includes the internal and external openings, as well as the fistula tract that connects them; therefore, simply using medication cannot completely eliminate this lesion. The treatment of anal fistula is mainly surgical, aimed at removing the local lesion, with the principle of preserving the anal sphincter to avoid damage to it, which could affect the patient's future life.