Summary of case history,　The patient, male, 65 years old, presented with "painful paranal swelling for 10 days." He was admitted to the Department of Anorectal Medicine of the People's Hospital of Fujian University of Traditional Chinese Medicine on 17 February 2023. He had been treated with "incision and drainage" at a local clinic (details unknown), but the result was not good. The pain gradually worsened and spread to the right side of the buttock, accompanied by chills and fever, and dyspareunia, so he came to us for treatment. He was admitted to the hospital with severe painful swelling around the anus and the right buttock, difficulty walking, flushed skin, no obvious darkening or necrosis, no bowel movement for 4 days, poor urination, red tongue, yellow and thick coating, and stringy pulse. The patient has a previous history of hypertension and chronic bronchitis.Examination: body temperature 36.3℃, pulse 84 times/minute, respiration 20 times/minute, blood pressure 99/60mmHg; no significant abnormalities in heart, lungs and abdomen. Specialist examination: the anal verge was not flat, the right perianal area and the right buttock were full and swollen, measuring approximately 15cm x 12cm. Three scattered 1cm x 1cm surgical incisions were visible on the skin of the anal verge, and a small amount of dark yellow foul-smelling pus was visible. The perianal and right buttock erythematous mass was painful to palpation, hard and felt like snow when touched, and the skin temperature was elevated where the mass was located. Preoperative examination suggested the presence of infection and hypoproteinemia.,TCM diagnosis,　Gangju,Reduchishengzheng.,Western medicine diagnosis,　Necrotizing fasciitis of the perianal area and right buttock,Hypertensive disorders,Chronic bronchitis,Hypoproteinemia.,Therapeutic methods,　On 17 February 2023, "perianal and right gluteal necrotizing fasciitis incision and drainage + pelvic drainage tube flushing" was performed under intra-vertebral anesthesia and general anesthesia. Postoperatively, he was given cefoperazone sodium sulbactam to combat infection, albumin supplementation, prevention of postoperative thrombosis and nutritional support. During the perioperative period, the internal Chinese medicine treatment was to benefit the qi and strengthen the spleen, clear heat and detoxify the pelvic area, reduce swelling and create muscle, and the Chinese medicine external treatment was to give external sitz baths with hemorrhoid elimination lotion, drainage by Chinese medicine threads and Chinese medicine rubbing.,Clinical outcomes,　Healed,.