A smaller anus after hemorrhoid surgery is caused by post-operative scar contracture from hemorrhoid surgery. Generally, if the anus becomes slightly smaller after surgery, it is not a big problem. Some scar patients will have more serious anal stenosis within a short period of time after surgery. 3-6 months after surgery is the softening period of the scars and the anal function will gradually return to normal. Of course, some patients do not retain enough skin at the anal margin during surgery or have postoperative infection resulting in skin bridge necrosis, which may lead to scar-induced anal stricture, and this kind of anal stricture often requires postoperative anal dilation treatment. Initial dilation treatment needs to be performed under the therapeutic guidance of a doctor 3-4 times a week for 10-15 minutes each time. Do not use rough force when dilation to avoid the impact on the trauma surface, which may cause hemorrhage or affect the healing of the trauma surface. After surgery, you should also eat a light diet, eat more coarse fiber food, and keep your stools soft and clear to prevent constipation.