A small amount of fecal overflow from the anus is considered an anal fistula. The clinical manifestation of anal fistula is the recurrent flow of purulent or mucus discharge and fecal water around the anus, which is caused by an infection of the anal sinus, followed by the formation of an internal opening, which continues to erode outward to form a fistula. The skin is connected to the internal opening through the external opening, so fecal water flows down the fistula into the perianal skin. It takes about a month and a half for the wound to heal after surgery, and it is normal to feel pain or swelling in the anus for the first half of the post-operative period. Even in the initial period after surgery, it is normal for the perianal area to be moist and have increased secretions. As the wound gradually heals, the secretion is gradually reduced. After the surgery, you must pay attention to rest and change the medicine regularly every day to develop good bowel habits.