Mr. Wang, 20, saw the advertisement of “minimally invasive hemorrhoid surgery” in a private hospital in Foshan 3 days ago and underwent “minimally invasive hemorrhoid” surgery in the hospital, complaining that he was “increasingly distrustful of the hospital He came to our hospital because he was “increasingly distrustful of the hospital”. The examination found that Mr. Wang’s entire anal canal had a circular defect of the migrating epithelium, without any preservation, and that the “minimally invasive surgery” was “complete” enough. However, what kind of sequelae will this so-called “complete” surgery bring to Mr. Wang? Let’s first understand the physiological characteristics of the migrating epithelium of the anal canal. The anal canal is the end of the digestive tract, and the upper end of the canal ends at the dentate line and meets the rectum, and ends downward at the edge of the anus. Thus, the narrow lumen from the anal verge to the end of the rectum is called the anal canal. The average length of the anal canal in adults is about 3 to 100 px above and below, while surgeons usually extend the upper boundary of the anal canal to 37.5 px above the dentate line (i.e., the plane of the rectal loop of the anal canal). The perimeter of the anal canal in our adults is approximately 250 px. The epithelial tissue of the skin of the anal canal is migratory flat or compound flat epithelium. The skin of the anal canal has a smooth surface and no sweat glands, sebaceous glands or hair follicles, i.e., “three-nothing” skin. The normal skin of the anal canal is loose and elastic. Therefore, it is easy to be pulled up when doing surgery under anesthesia, and therefore too much skin of the anal canal is easily removed to cause anal stenosis. Therefore, special attention should be paid to protect the skin of the anal canal during surgery. When too much skin is removed from the anal canal, as the wound gradually heals, the fibrous scar tissue proliferates and causes contraction of the anorectal outlet, and when it is completely healed, the excessive fibrous scar tissue lacks elasticity and leaves a narrow outlet. The clinical symptoms caused may be thinning of the stool and difficulty in passing stool when dryness is encountered. It can also cause a series of symptoms such as overflow of fluid secretion from the glands in the rectum leading to dampness of the anus and underwear. Anal stenosis can be prevented. When hemorrhoid surgery is performed, it should be better to preserve as much of the inter-skin bridge of the anal canal as possible, even if one inter-skin bridge is preserved, than none at all. This way the possibility of postoperative anal stenosis will be minimized and the function of the anus will be protected to the maximum extent. Therefore, it is important to explain the importance of “surgical excision versus functional protection” and the possibility of temporary edema of the preserved skin bridge to the patient before surgery. Mr. Wang was only 3 days postoperative and it would take 1 month for the wound to heal completely. He was given herbal sitz baths and herbal ointments for external use, and was instructed to eat a normal diet, defecate daily, and dilate his anus naturally through normal formed stools. If stenosis is found, early anal dilation; if severe stenosis is found, anal flap plasty is feasible. In case of anal diseases or doubts, we still recommend to visit a qualified hospital or doctor and ask more questions about why, so that minor surgery for minor diseases will not cause serious complications.