Submucosal fistula without an external opening is not easy to treat. There is no external mouth of the submucosal fistula examination and treatment are more difficult, and easy to recur after treatment, so it is not very good treatment. There is no external fistula is easy to form multiple fistula, and there is no external fistula can not use the probe to check the direction of the fistula and the number of lines, to find the inner mouth of the difficulty is higher, often need to carry out pelvic floor MRI to find the direction of the fistula and the inner mouth, the difficulty of surgical treatment is higher. Examination found that there is no external fistula, patients need early treatment, so as to avoid the increase in the number of fistulas, increasing the difficulty of treatment and prolonged infection can cause significant impact on the patient’s body and damage. After the anal fistula surgery, patients need to pay attention to keep the local clean, usually wash their underwear to avoid bacterial infection, follow the doctor’s instructions, as far as possible to reduce the chance of recurrence of anal fistula.