After 6 months of hemorrhoid surgery, sudden pain in the anus during bowel movement may be due to constipation, poor healing of surgical wounds, anal fissure, etc., which needs to be treated in conjunction with the specific situation. 1. constipation: the occurrence of hemorrhoids, and the patient constipation and other defecation abnormalities related. After surgery, if the patient does not pay attention to self-protection, there are still dry stools, constipation, etc., the defecation process, defecation effort, will increase the pressure on the anal canal, the anus, may induce sudden pain in the anus. 2. poor healing of surgical wounds: hemorrhoid surgery is more, if you take the traditional external peeling and internal ligation surgery, the surgical wound is relatively large, the healing time is relatively long. If poor healing occurs, during defecation, especially when the stool is dry, the feces may open the surgical wound, resulting in sudden pain. 3. Anal fissure: the patient’s wound heals well after surgery, but if there is persistent difficulty in defecation. As the surgical wound healing area is weak, stimulated by the injury, it may lead to anal skin tearing, small ulcers, anal fissure wounds appear, resulting in sudden pain in the anus when defecating. Hemorrhoid surgery 6 months after the phenomenon of anal pain in the stool, it is recommended that patients go to the hospital in a timely manner to check, to clarify the cause of the disease, to give relevant treatment.