An anal fistula is the presence of a fistula at the patient’s anus, which can lead to repeated local breakdowns and pus flow, accompanied by painful, inflammatory masses, etc. Most anal fistula surgeries are minor surgeries, but if the patient is a complex anal fistula, it is a major surgery, as follows: 1, minor surgery: for simple anal fistula, that is, there is an internal mouth and an external mouth, the effect of surgical treatment is better, belongs to the minor surgery, according to the height of the internal mouth, you can choose anal fistula hanging surgery or fistula removal surgery and so on. 2, major surgery: If it is a complex anal fistula, such as multiple internal and external ports, this is a major surgery, an operation does not solve the problem, may have to carry out multiple operations.