Anal and intestinal diseases are common and frequent diseases that are unique to humans. In a broad sense: all kinds of diseases occurring on the anus and large intestine are called anorectal diseases, and there are more than 100 kinds of common diseases. In a narrow sense: various diseases occurring in the anus and rectum. A, perianal infectious diseases perianal abscess, anal fistula is a common perianal infectious diseases in infants and young children, the main reason for the onset is the physiological structure of its special, because the pediatric sacral bend has not yet formed, the rectum and anal canal is vertical, direct pressure of feces at the anal canal dentate line anal sinus, easy to cause anal sinus injury infection inflammation; acute and chronic diarrhea, too many bowel movements; pediatric perianal diaper dermatitis, perianal skin unclean, can also lead to perianal infection; and then the chronic diarrhea, too many bowel movements. It can also lead to perianal infection; furthermore, the low immunity of children is also the main cause of infection. Preventive measures: ③ Wash the anus after defecation, keep the anus clean and reduce the stimulation of the anus. Second, pediatric anal fissures The main cause of pediatric anal fissures is caused by bad bowel habits or improper feeding, constipation or dry and hard stool tearing the anus and anal fissures occur. It is characterized by fear of defecation, crying during defecation, and blood in the stool. The fissures can be seen on examination, with most occurring on the posterior side of the anal opening, followed by the anterior side. Preventive measures for pediatric anal fissures: ①Choose appropriate milk powder, eat more fiber-rich foods, drink more water, prevent constipation, and keep the bowel movements smooth and regular; ②Use soft handkerchiefs as much as possible and move gently to avoid rubbing the anus of children. ③ Wash the anus after the stool, keep the anus clean and reduce the stimulation of the anus. Third, pediatric rectal prolapse pediatric weakness, as well as pediatric pelvic tissue is not fully developed, the sacrococcygeal bone can not fully rely on and support the rectum; coupled with general malnutrition, weak muscles around the rectum, when the abdominal pressure increases, the loss of rectal support fixed role, resulting in rectal prolapse. In addition, the patient in the bowel movement too hard, abdominal pressure increases, squatting for a long time, coupled with children prone to crying, diarrhea and constipation and other factors, can make the rectal mucosa and muscle layer separation. Therefore, the long diarrhea of young children and the elderly, are prone to fix the rectum of the surrounding tissue relaxation, resulting in prolapse. Over time, the prolapse becomes larger and larger, and the anus becomes flaccid. Preventive and curative measures: ① we should pay attention to improving the general condition and correcting malnutrition; ② oral administration of traditional Chinese medicine, acupuncture, and fumigation with astringent and solid herbs; ③ injection treatment can be used only if conservative treatment is not effective. Polyp is the main cause of blood in the stool of infants and young children, the most common polyps in infants and young children is juvenile rectal polyps, no pain, but every bowel movement bleeding, generally no other clinical symptoms, polyps increase in size when defecation can see the purple meat. Juvenile polyps will fall off on their own and also have the tendency to become cancerous, so they should be actively diagnosed and treated after discovery. Fifth, other congenital diseases congenital megacolon, which 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 lost regular peristalsis, constipation, abdominal distension after birth, if not early diagnosis and treatment can occur colitis, or even intestinal perforation and life-threatening. Congenital anorectal dysplasia is commonly known as congenital anuslessness. 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 associated with a deficiency of the anal sphincter, which controls defecation and directly affects the quality of life.