High anal fistula is a fistula above the deep outer sphincter, including simple and complex types, manifested by the external opening of the fistula draining fluid and gas. Anal fistula is a granulomatous tube around the anorectum consisting of an internal opening, a fistula, and an external opening. Young and middle-aged men are more likely to suffer from high anal fistula. High anal fistula means that the fistula is located in the deeper part of the external anal sphincter above, if there is only a fistula, it is simple anal fistula, there are multiple fistulas and fistulas for complex anal fistula. High anal fistula can be manifested as a fistula external mouth intermittent or persistent discharge, can be mucous, purulent or bloody. High anal fistula is not limited by the external sphincter, but also may appear to discharge gas or fecal manifestations. At the same time can be accompanied by perianal skin pain, itching, moisture and so on. If there is pus and fluid overflow from the perianal skin, recurrent episodes, accompanied by other discomforts, it is recommended to consult a doctor in time for diagnosis and treatment.