In our clinical work, we encounter many patients with anal fistulas, usually with a history of several years, but who do not know what they have. This indicates that anal fistula is a disease that many people do not yet understand. The two pathological stages of perianal septic infection are anal abscess and anal fistula, which are called anal fistula in the acute phase when the pain is obvious and in the chronic phase when the abscess breaks down. Modern medicine believes that the main causes of anal fistula formation are: 1. perianal abscess, i.e. perianal abscess. This is the main cause of anal fistula, which is formed due to infection of the anal glands. 95% of all anal fistulas are caused by this. 2, anorectal injury. Injuries to the anal canal caused by foreign bodies can directly form fistulas. 3, anal fissure caused by repeated infection of the anal glands, forming perianal abscess, and then the formation of anal fistula. 4, poor healing of surgical wounds in the perineum and the formation of fistulas. 5.Bloodstream infection. With diabetes, hemophilia, aplastic anemia and other diseases, bloodstream infection can cause anal fistula due to the low resistance of the body. 6, other diseases. It is not uncommon for tuberculosis to be complicated by tuberculous anal fistula. About 5% – 20% of rectal cancer is also often complicated by anal fistula. Most anal fistulas are formed by perianal abscesses, so the infection period of anal fistula is manifested as abscess symptoms. After the abscess dissipates and the fistula is formed, the main symptom is a local discharge. Patients with anal fistulas most often describe intermittent and repeated purulent blood discharge around the anus and hard lumps or cord-like nodules around the anus to their own touch. Occasionally there is pain, which is significantly reduced when the discharge overflows. When the diagnosis of anal fistula is confirmed, it is necessary to treat it surgically. The main types of surgery for anal fistula are as follows: 1. excision of anal fistula, which is suitable for superficial, short, straight and thin fistula. 2. The fistula is superficial, the fistula is thick, and the fistula is excised. 3.Anal fistulotomy with wire is suitable for fistulas with deep internal orifices, fistulas that may pass through the anal sphincter and complex fistulas. If you have the above symptoms, you should go to the hospital’s anorectal department in time for early surgical treatment. If you are too long delayed, you will have a simple fistula that becomes a complex fistula, and a simple fistula that becomes a complex fistula with multiple fistulas. In addition, the repeated inflammatory stimulation of anal fistula may also have the possibility of cancer.