The location of the internal opening of the fistula is too high, i.e. high anal fistula, which is generally more likely to form perianal abscess, perianal eczema, cancer and other problems. 1. Perianal abscess: high anal fistula due to the fistula is located in the deeper part of the external anal sphincter, so when the fistula attack may lead to perianal abscess, and may even spread upward, causing the infection to expand, and even cause bacteremia or sepsis and infectious shock. 2. Perianal eczema: high anal fistula causes fistula not controlled by sphincter muscle, which leads to feces and other fecal matter flowing out from the external opening of fistula, resulting in itching, moist and other symptoms of perianal skin, and eventually forming perianal eczema. 3. Cancer: If high anal fistula is left untreated for years, repeated infections and stimulation may induce the possibility of cancer. Therefore, it is recommended that once the high anal fistula is found, it should be treated with surgery in time. In the operation to explore the internal opening, find the fistula and completely remove, hang the drainage cutting and so on. After the operation, attention should be paid to the sterilization and dressing change of the wound to prevent false healing.