After anal fistula surgery, the incision bulging a soft bag white squeeze can be pus and blood, considering the possibility of postoperative infection. Anal fistula surgery for drainage, the incision is open, plus the anus is feces and dirt outlet, will increase the possibility of infection, when the incision appeared a pus and blood bag, consider the occurrence of postoperative infection, available erythromycin ointment can be coated, can play a role in anti-inflammatory and reduce swelling, postoperative can also be used in the sitz bath of 1:5000 potassium permanganate solution, have a clean and anti-inflammatory effect. At the same time, we should change the medication on time and have regular checkups, and after the inflammation is eliminated, the soft bag will disappear on its own. In order to prevent the above symptoms, you need to pay attention to the perianal hygiene in normal times, wash with warm water in a timely manner after the stool, eat a light diet, and keep the stool smooth and soft. And also moderate exercise, enhance physical fitness, can help to reduce the attack, and prevent discomfort,.