The size of the drainage gauze used after anal fistula surgery is not fixed, mainly based on the depth and size of the trauma is decided, in order to fully fill the trauma, leaving no dead space is appropriate. According to the location of anal fistula surgery is divided into low anal fistula, high anal fistula, or complex anal fistula and simple anal fistula, according to the specific circumstances of the operation need to be anal fistula fistula fistula completely excision, cut, so in the postoperative wound more larger and deeper. In order to facilitate adequate drainage of the postoperative wound, the wound needs to be fully filled with drainage gauze, but also can play a role in compression, hemostasis. Especially for deeper wounds, the drainage gauze should be stuffed to the bottom of the wound to avoid the formation of a dead space, which will affect the drainage of internal secretions, so there is no absolute size standard for the drainage gauze, depending on the needs of the disease. To summarize, the size of drainage gauze to be used should be determined by a professional doctor according to the specific condition, and it is not fixed, and should not be used indiscriminately on one’s own.