The main symptom of anal fissure in children is blood in the anus during defecation, which is fresh blood, not much, often a few drops at the end of defecation, sometimes only blood is attached to the surface of the stool, or there is blood on the stool paper. If parents do not intervene in a timely manner, the child will be afraid to defecate for fear of pain, which in turn will aggravate the dryness of the stool, make the next defecation more painful, and make the defecation more difficult, thus entering a vicious circle and making it difficult to heal the fissure. Most pediatric anal fissures are caused by chronic constipation and dry, hard stools, resulting in transitional expansion of the anal opening and tearing when the child is forced to defecate, but only a very few are caused by other diseases. The author believes that it is related to functional constipation caused by imperfect bowel function and insufficient intake of dietary fiber in complementary foods. Due to the special anatomical characteristics of children, pediatric anal fissures can occur in any direction of the anal canal, with girls most likely to occur in the front of the anal canal. If the injury is followed by recurrent infection, it can lead to “sentinel hemorrhoids”. Sentinel hemorrhoids are repeated anal fissures that lead to inflammation and edema of the skin tissue distal to the fissure, resulting in an inflammatory proliferation of local granulation tissue and the formation of a small bulge protruding from the anus. Sentinel hemorrhoids resemble external hemorrhoids in morphology, but unlike hemorrhoids, their contents are not thrombosed and coexist with anal fissures; they are only one of the features of chronic anal fissures. Generally sentinel hemorrhoids do not require special treatment or even surgical removal, and they usually gradually improve and heal as the anal fissure gets better. Treatment: The main treatment for the cause is to regulate the diet, soften the stool and prevent it from drying out. The second treatment is to reduce the pain of defecation and promote the healing of the wound. Diet should increase the intake of dietary fiber-rich foods, increase water intake, and if necessary, take oral medication to regulate the gastrointestinal tract and soften stools. Improve bowel habits: Make sure your child has regular bowel movements every day, not once every 3-5 days. If the anal fissure is not serious, take a sitz bath with warm water or (a small amount of) salt water after the stool. If necessary, apply open cork to assist the child to defecate. If the fissure is prolonged and painful, 0.5% procaine can be used to close the fissure once every other day. If the above treatment does not work, excision can be considered, and after surgery to keep bowel movements and frequent sitz baths, but children are generally rarely serious enough to require surgical excision, generally after careful parental care, as the child slowly grows, the disease will be gradually cured.