Many people may think that children are not prone to anal diseases. In fact, due to the special physiological characteristics of infants and young children, they are often prone to anorectal diseases. Especially anal fistula diseases, so what are the several common anorectal diseases in children? Type I: congenital megacolon It is the lack of ganglion cells between the submucosa and muscle of the rectum, colon, and even small intestine of the fetus, the sick intestine loses regular peristalsis, the newborn is born with constipation, abdominal distension, if not early diagnosis and treatment can occur colitis, or even intestinal penetration and life-threatening. Type 2: congenital anorectal malformation commonly known as congenital anus. It is a fetal anorectal development problem that fails to form a normal anorectum, which is divided into three types: high, medium and low. The disease is often accompanied by a deficiency of the anal sphincter that controls defecation, which directly affects the quality of life. Type III: Anal fistula An anal fistula is a perianal infection caused by skin bacteria or intestinal bacteria, and rarely by Mycobacterium tuberculosis infection or trauma. Some female infants have anal rectovestibular fistulas also due to bacterial infections. Type IV: Rectal polyps The most common cause of pediatric blood in the stool is rectal polyps, which is also the most common disease in pediatric anorectal surgery and can account for about 30% of cases. Its formation may be related to genetic factors, inflammation (such as dysentery), mechanical chronic irritation (constipation, rough stool), viruses, etc. The polyp is usually shaped like a small grape with a tip, with a color ranging from light red, dark red to purple, with a surface like the thorns of mulberry or prune, single or multiple, near or far from the anal opening, and sometimes brought out to the outside of the anus by defecation. The blood in the stool caused by these polyps is usually bright red in color and adheres to the surface of the stool without mixing with each other, and it is rare to see a simple bloody stool without fecal matter. On closer inspection, groove-like indentation can be seen on the stool, which is caused by the passage of stool through the polyp. Children usually do not have abdominal pain, urgency, etc. A small amount of bleeding over a long period of time can cause anemia in children, and polyps may also cause intestinal peristaltic disturbance and induce intussusception. Type 5: Anal fissure Mostly caused by dry stool, often occurring in the back of the anal canal, the fissure can be seen by slightly separating the anus with both hands, bleeding in small amounts, bright red, attached to the surface of the stool or visible on the hand paper; severe pain during defecation, children cry and do not want to defecate, which makes the stool even drier, causing anal fissures to persist. Type 6: perianal abscesses Children, especially newborns and infants, have delicate skin, which can easily be caused by the invasion of purulent bacteria due to urine and feces impregnation, friction of coarse, hard and unclean diapers, and damage from rough handkerchiefs. The whole body may also be feverish, and the child may cry, refuse to eat, and vomit. If left untreated, pus may break down and form an anal fistula. Type 7: Anal itching A common disease of pediatric anal itching is pinworm disease. Pinworms are parasitic in the intestinal tract and females often crawl out of the anus at night to oviposit. The eggs contaminate the fingers and clothing and then enter the digestive tract either directly or through raised dust and then develop into adult worms, so repeated infections of their own or infect others occur. Anal itching often occurs at night and affects sleep. Parents can examine the skin folds around the anus 2-3 hours after the child falls asleep and can find white thread-like adult worms. Type 8: Prolapse The rectum and anal canal of infants and young children are in a straight line, and the surrounding tissues are loose and the muscles are weak (especially in malnourished children or children with digestive diseases), so they start to sit on the potty to defecate around the age of 2. The prolapse can be easily caused by constipation, prolonged sitting in the basin, or frequent diarrhea, or increased abdominal pressure such as coughing, cystocele or urinary bladder stone. Initially, prolapse only occurs when using force to defecate, and it can be retracted automatically after defecation, and later it may need to be sent back with the help of hands. If it is not returned for a long time, edema, oozing, and ulceration may occur, causing swelling, pain, urgency, and flow of pus and mucus. The vast majority of children with prolapse can heal themselves by age 5.