Perianal abscess and anal fistula are common clinical diseases of the anus. Generally, people diagnose most painful diseases of the anus as hemorrhoids by themselves, while there is not much awareness of perianal abscess and anal fistula, and some people think that these are two diseases, but in fact they are two stages of one disease, different stages, called by different names only. Perianal abscess is the result of an acute purulent infection of the soft tissues around the anorectum. The vast majority of perianal abscesses originate from infection of the anal glands, with a very small percentage resulting from other factors. Perianal abscesses can develop at any age, but are more common in young and middle-aged people between the ages of 20 and 50, more in men than in women, and can also develop in infants and children. The onset of perianal abscess is sudden and fast progressing, causing severe local pain around the anus and fever and other systemic symptoms in severe cases, and the abscess often forms an anal fistula after the abscess breaks down or after surgical incision and drainage. It is often treated as a clinical emergency because timely and aggressive treatment can not only reduce the patient’s pain but also avoid aggravation and complication of the condition. A typical anal fistula consists of a primary internal port, a fistula tube, and an external port, characterized by an internal port located at the dentate sinus, a fistula tube located in the perianal tissue between the internal and external ports, and an external port located in the perianal skin with frequent purulent discharge. If the external opening is not closed, the discharge may cause local swelling and pain, and then the external opening may re-rupture or pus may flow out after forming a new external opening nearby, and so on repeatedly. This disease is a common disease in anorectology, accounting for 3% to 5% of general surgical diseases, and can recur and persist. Treatment of perianal abscesses and fistulas: Once a perianal abscess is formed, early surgical cure or incision and drainage is desirable to prevent the spread of the lesion and complicate the disease. Delayed treatment may turn a simple perianal subcutaneous abscess into a complex deep abscess, making surgery more difficult, prolonging postoperative wound healing time, and making a one-time curative surgery possible into a second or multiple surgeries. Moreover, multiple surgeries are likely to cause irreversible damage to the anal sphincter and deformation of the anal shape. Many patients are psychologically unable to accept surgical treatment and ask for anti-inflammatory medication on their own, but the inflammation may be reduced and the symptoms relieved after the infusion, but generally the purpose of the cure cannot be achieved, and the disease will recur after a few weeks or months, repeatedly. Repeated chronic inflammatory stimulation may lead to cancer after a long time, and we have seen such cases in the clinic. The traditional cure for perianal abscess and fistula is to cut open all the internal orifices, pus cavities and fistula tubes so that the drainage is unobstructed, which is especially suitable for those with small lesions, but when the lesions are extensive, it is necessary to cause large or complex incisions, which often leads to slow healing and causes greater pain to patients, and sometimes even deformation and displacement of the anus due to scar contracture after healing. The main focal incision and counter-oral drainage method in An’s therapy is an innovative surgical method for treating perianal abscess and complex anal fistula, which has the advantages of less damaged tissues, faster wound healing, shorter treatment course and less scarring. In the case of perianal abscess, the internal opening is the main focal point, and the location and size of the main focal incision and other incisions are based on the principle of making the pus cavity drainage smooth, which can also achieve the effect of reducing trauma and protecting anal function and appearance. Low incision and high latex tube drainage is a classical method for the treatment of high perianal abscesses and high anal fistulas by An’s therapy. This method avoids the prolonged pain caused by continuous strangulation by traditional hanging, without incision or partial incision of the rectal ring of the anal canal, with less damage compared with hanging and without the risk of anal incontinence. Moreover, as long as the internal opening and high lesion are all open and drainage is complete, the postoperative recovery is generally faster and non-recurring, and the scar is lighter after the wound healing, which does not affect the appearance of the anus.