The main symptoms of anal fistula are perianal pus, pain and itching. An anal fistula is an infectious disease that refers to a granulomatous tube around the anal canal or rectum. After the formation of an anal fistula, the patient will mainly have purulent secretions around the anus, and these secretions constantly irritate the skin, which can cause symptoms of itching of the skin around the anus, and sometimes eczema is also formed. When there is abscess formation in the fistula, the patient can feel obvious pain and swelling. Most anal fistulas are caused by an abscess around the rectum and anal canal, which breaks down and forms an external opening in the perianal skin, intermittently and repeatedly flowing pus and causing an anal fistula. Some diseases such as ulcerative colitis, Crohn’s disease, malignant tumors, traumatic infection of the anal canal can also cause anal fistula, in addition, sedentary, late at night, alcoholism and other bad habits can also induce anal fistula. It is recommended that patients with the above symptoms, timely to the hospital, under the guidance of a professional doctor for treatment, to avoid repeated episodes affect normal life.