More than 2 months after anal fistula surgery, there is a lot of blood coming out of the anus after bowel movement, which may be related to poor wound healing, pseudo healing, other anorectal lesions, and need to be diagnosed after the cause of the general treatment, medication, and surgery and other treatments. 1. poor wound healing: anal fistula is one of the common anorectal lesions, the condition is relatively complex, most patients need surgical treatment. Commonly used surgical programs include anal fistula fistula resection, anal fistula incision and drainage. Poor healing of the wound after surgery and defecation may lead to heavy bleeding. It is necessary to keep the wound clean and hygienic, eat a reasonable diet, keep the bowel clear, prevent blood in the stool, and promote the healing of the wound. 2. False healing: If the patient has false healing, an abscess lesion will form in the surgical area. During defecation, this causes the abscess to rupture and bleed, and heavy bleeding in the stool may occur. After diagnosing the cause, it is necessary to incise the abscess cavity, remove the pus, combined with sensitive antibiotic anti-inflammatory treatment, such as cefixime, penicillin, metronidazole and other drugs, to ensure smooth recovery of the surgical wound and achieve hemostasis. 3. Other anorectal lesions: If the patient has hemorrhoids, anal fissure, anorectal polyps and other anorectal lesions, it may also lead to bleeding in the stool. Detailed examination is needed to confirm the diagnosis of the condition, through the cause of the symptomatic treatment, to achieve the therapeutic purpose. It is recommended that patients with the above conditions should consult the doctor in time to get a clear diagnosis and follow the doctor’s instructions to give reasonable and standardized treatment to avoid delaying the condition.