Three months after anal fistula surgery, a red, swollen and particularly painful wound may be the result of a wound infection that has occurred. Anal fistula surgery involves surgically cutting or removing the infected granulomatous tube around the anus that has persisted for a long time. Anal fistula surgery is relatively simple, there is pain and a small amount of bleeding after the operation, about one month after the operation can return to normal. Three months after surgery, the wound appears red, swollen, painful symptoms, indicating the occurrence of infection, may be because of the postoperative not pay attention to local hygiene and cleanliness or the patient’s resistance is low, resulting in bacterial invasion, causing wound inflammation, serious abscess formation, need to be incised and drained. After anal fistula surgery this symptom should be timely to the hospital, improve the relevant examination to clarify the cause of the disease, under the guidance of the doctor’s symptomatic treatment, to avoid unauthorized use of drugs, delay the aggravation of the condition.