Anal stenosis surgery involves the use of an electric knife to radially incise the stenosis area at least four points and then dilate the anus to achieve the treatment goal. Anal stenosis is usually caused by scar formation after hemorrhoid surgery, which often manifests itself as difficulty in defecation after recovery from surgery, and a sense of incompleteness after defecation when you are still able to pass a thin stool. In this case, if the diagnosis is clear, you can first use anoscopy or anal expansion rod to expand the anus, if the effect of anal expansion is not good, then you need to carry out surgical treatment. Anal stenosis is often categorized into tubular stenosis and membranous stenosis. Surgery for membranous stenosis only requires radial incision of at least four points in the stenosis, and part of the internal anal sphincter can be incised if necessary, and then anal dilation can be performed using anoscope. Tubular stenosis is a slightly more complex procedure and is relatively less effective. It also involves radial incision of at least four points, as well as removal of as much scar tissue as possible that is causing the stenosis, and a final injection of tretinoin to soften the scarring. Surgery for tubular stenosis is more invasive than surgery for membranous stenosis, and there is a high likelihood of re-scarring and stenosis after surgery, which still requires adherence to anal dilatation therapy. Anal stenosis surgery, depending on the individual’s condition, the clinician will choose a reasonable surgical operation.