Anal fistula is a sequel to the natural breakdown or incision and drainage of a perianal fistula abscess, which cannot heal on its own. In the early stages of fistula formation, the patient can be asymptomatic and only have a hard node in the perianal area, or have symptoms such as intermittent perianal overflow, anal dampness, etc. When the hospital diagnoses “fistula” and recommends surgery, it is always a fluke to avoid surgery, which can lead to serious consequences. In fact, if the primary lesion is not removed, it is like a hidden “invisible bomb”, and when it strikes again, the condition is already complicated. The reason for this is the special location of the anal canal rectum, which is frequented by feces and bacteria every day, and the muscle of the anal canal rectum is often in a state of relaxation and contraction, coupled with poor habits such as unclean diet, diarrhea, alcohol and spices, which can lead to the development of a complex anal fistula. Complex anal fistula, especially high complexity anal fistula, is a more difficult disease to treat internationally, because the tube is deep in the sphincter, the location of the internal mouth is complex, and it is extremely difficult to detect the direction and location of the internal mouth. For patients whose primary lesions are temporarily in a stable state and whose internal openings are closed, it is impossible to determine the correct location of the internal openings, so there is a certain risk of recurrence in surgery, and it is difficult to avoid damage to the perianal sphincter if too many canals are removed because of the complex canals that run between the perianal sphincter. Once an anal fistula is formed, it should be treated with surgery as early as possible. Surgery is the only way to cure an anal fistula, and at this time, the primary lesion is clearly traceable, the canal is simple, and the damage to the perianal sphincter is minimal, which will not affect the function of the anus and the recovery time is shorter. Some studies have shown that repeated anal fistula infections over many years can worsen and seriously affect physical and mental health. Therefore, surgery for anal fistulas should be performed early to avoid complications. For patients with complicated anal fistulas, the current medical opinion is that it is appropriate to remove the fistula in separate surgeries if necessary for the purpose of protecting the anal sphincter, and for patients with high surgical risk who cannot be surgically removed, survival with fistula and outpatient follow-up are advocated.