The etiology of pediatric diarrhea is complex and can be divided into infectious and non-infectious diarrhea. Infectious factors include viruses, bacteria, fungi and parasites; non-infectious factors include symptomatic diarrhea, allergic diarrhea, food-bait diarrhea, inflammatory bowel disease, etc. Bacteria cause diarrhea in babies, the following 2 kinds are common: (1) enteritis caused by toxic bacteria: mostly occurs in summer, the onset of the disease is more acute. Mild cases have a slightly increased number of stools and a slight change in character. In severe cases, diarrhea is frequent, abundant, watery or egg-flake soup-like, with mucus and fishy odor. With fever and vomiting, dehydration, electrolyte and acid-base balance disorders often occur. Stool microscopy shows fat globules, mucus and a few white blood cells. The duration of the disease is 3~7d, but it may be longer. (2) Enteritis caused by invasive bacteria: can develop throughout the year, mostly in summer. The onset is rapid, with high fever, and febrile convulsions may occur. Diarrhea is frequent, the stool is yellow, yellow-green, mucus-like, with pus and blood, with a fishy odor. It is often accompanied by nausea, vomiting, abdominal pain and shortness of breath. In severe cases, dehydration, acidosis, systemic toxic symptoms and even infectious shock may occur. Treatment should pay attention to reasonable diet and nutrition, rapid correction of water and electrolyte balance disorders, control of infection inside and outside the intestinal tract, symptomatic treatment to enhance care and prevention of complications, and avoid abuse of antibiotics. Dietary treatment: continue to breastfeed infants with mild cases, appropriately limit the number of nursing sessions or shorten the duration of each nursing session, and suspend complementary foods; artificially fed children can be fed with equal amounts of rice soup or diluted milk or other milk substitutes, and gradually transition from rice soup, congee, noodles, etc. to a normal diet. During the diarrhea period, continue to eat and give the baby a normal diet appropriate to its age, and do not “fast” as much as possible, as fasting can lead to prolonged symptoms and loss of nutrition. Correction of water and electrolyte disorders: (1) Oral rehydration salts (ORS) are suitable for children who are mildly or moderately dehydrated and can eat; intravenous rehydration is suitable for those with severe vomiting and diarrhea, abdominal distention and moderate dehydration or above. (2) Correct acidosis and electrolyte disorders. Drug treatment: (1) the rational use of antibiotics: general watery stool can be used without antibiotics, mucus stool, pus and blood stool can choose antibiotics, mainly oral second and third generation cephalosporin antibiotics. With a full course of treatment, not without the consent of the doctor to stop the drug. (2) microecological therapy: through the restoration of the human intestinal microecological balance, to achieve the purpose of treatment of intestinal diseases. (3) Adjuvant therapy: intestinal mucosal protective agents, intestinal dynamics inhibitors, antisecretory drugs, etc.