The main hazards that may occur after mixed hemorrhoid surgery are the following: 1. Post-operative bleeding, especially in more serious mixed hemorrhoids, can occur when the ligature line falls off prematurely after surgery. 2. Incomplete anal sphincter, when the external sphincter is removed during hemorrhoid surgery and even the anal lift muscle is cut off together, can cause incomplete anal sphincter, resulting in anal incontinence and an increased number of bowel movements. 3. If the skin of the anal canal is damaged too much during the hemorrhoid surgery, it will cause scarring stenosis and eventually cause anal fissures. 4. If the hemorrhoid surgery is not treated properly, it will also lead to scar contracture around the anus, causing difficulty in defecation.