Generally the closer the outer opening of the fistula is to the anus the lower the inner opening is. Anal fistula is composed of three parts: internal mouth, fistula and external mouth, of which the external mouth is closest to the anus. Clinically, if it is a simple low anal fistula patients, anal fistula external mouth from the anus is very close, about 1 ~ 2 cm, such patients fistula internal mouth is also lower, generally better treatment. If the patient’s fistula is far from the anus, it is often suggested that the patient’s fistula is deeper, the inner mouth is higher, belonging to the high level of anal fistula, generally more complicated to treat. Fistula can lead to the patient’s anal area pus, bloody secretions, often difficult to self-healing, such as patients check out the fistula, should be early surgery to remove. After surgery should take good care of the wound, pay attention to regular medication, at the same time, pay attention to avoid eating spicy stimulating food, keep bowel movement.