The patient was admitted to the hospital on October 13, 2011, 3 months after perianal abscess incision and drainage, with an anal fistula opening 100px outside the anal margin at 7 o’clock in the anal truncus position, with a diameter of 20px and granulation tissue hyperplasia at the opening. The internal orifice was located 25px above the anorectal ring at 6:00, and a fistula was found between the internal and external orifices, with fibrosis of the anorectal ring. The patient felt significant abdominal distension on the second postoperative day, accompanied by lumbosacral distension and pain, but no special treatment was performed. The diagnosis was widespread subcutaneous emphysema of the thoracic and abdominal walls, which was considered to be related to the surgery. Discussion: Postoperative complications of subcutaneous emphysema after anal fistula are rare, and up to now, large subcutaneous emphysema after high anal fistula has not been reported in China. When the patient’s abdomen is distended, the gas pressure in the intestinal cavity may increase and enter the subcutaneous tissue along the surgical wound or fistula, and then diffuse to all parts of the body to form a subcutaneous emphysema, and when the abdomen is severely distended after surgery, the intra-anal gauze should be removed in time or a drainage tube should be placed at the same time to prevent the occurrence of subcutaneous emphysema. Zhang Dongxing, Department of General Surgery, Guizhou Provincial People’s Hospital