Hemorrhoids can be treated with surgery, some patients will be left with small sarcoma in the anal opening after surgery, which should be caused by the following factors: 1, post-surgical edema, due to surgical stimulation and local inflammatory reaction, some patients will have obvious anal papilla edema after surgery, which will be detached outside the anus to form sarcoma. 2, post-surgical scar hyperplasia, due to the difference in physical condition or post-surgical infection of the incision, the granulation tissue or fibrous Due to the difference of physical condition or postoperative infection of incision, granulation tissue or fibrous connective tissue overgrowth will form obvious raised scars.3, lymphatic fluid retention, the surgery will damage the blood vessels and lymphatic vessels in the anal canal area, and after the surgery, the lymphatic fluid reflux is blocked, which will accumulate in the local area and form a small sarcoma.4, recurrence of hemorrhoids after the surgery, if the ligation of hemorrhoids is incomplete during the surgery or the patient is constipated for a long time after the surgery, which will cause hemorrhoids recurring, and then the formation of sarcoma again.