There is a soft bag at the wound after anal fistula surgery, which may be caused by subcutaneous tissue proliferation, recurrence and other factors. 1. subcutaneous tissue proliferation: anal fistula, also known as anorectal fistula, is a common clinical anorectal disease, is a granulomatous inflammation formed by perianal rectal abscess. The main manifestations are pain in the perianal abscess lesion area, perianal skin ulceration, inflammation, pus and so on. The local inflammatory reaction after surgery can cause secondary changes, leading to local subcutaneous tissue proliferation, which can form a soft bag. 2. Recurrence: after anal fistula surgery, there is a certain recurrence rate in the clinic. The location of the anal fistula is relatively high, if only dealt with the low anal fistula, the location of the high fistula is not dealt with, can lead to postoperative recurrence. Postoperative medication change is not pay attention to, may lead to false healing, is also the main cause of recurrence of the disease, manifested in the wound with a soft bag phenomenon. It is recommended that patients follow the doctor’s instructions after anal fistula surgery, regular sitz bath and change the medicine, pay attention to the observation of postoperative symptom changes, such as abnormal manifestations, if necessary, go to the hospital for review, timely treatment, to avoid aggravation of the condition.