Baby diarrhea, also known as infantile dyspepsia, is an acute gastrointestinal dysfunction in infancy and early childhood. It has the highest incidence in the summer and fall, with diarrhea and vomiting as the main symptoms. Baby diarrhea can be cured quickly with proper treatment. However, it can be life-threatening if left untreated to the point of severe water-electrolyte disturbances. The causes of diarrhea in babies are divided into three areas: physical, infection and digestive disorders. 1, physical factors (1) infant gastrointestinal tract development is not mature enough, enzyme activity is low, but the nutritional needs are relatively more, the gastrointestinal tract is heavy burden. (2) The development of neurological, endocrine, circulatory system, liver and kidney functions are immature in infancy, and the regulation function is poor. (3) The immune function of infants is also not perfect. The antibody titer of serum E. coli is the lowest from birth to 2 weeks of age and gradually increases later. (4) The distribution of body fluids in infants is different from that of adults, and the proportion of extracellular fluids is higher, and the water metabolism is vigorous, and the regulation function is poor, so it is easier to have disorders of body fluids and electrolytes. Infectious factors are divided into internal and external infections in the digestive tract, with the former being the main one. (1) infection in the digestive tract: pathogenic microorganisms can enter the digestive tract of children with contaminated food or water, often occurring in the process of artificial feeding of children. (2) Infections outside the GI tract: Infection of organs and tissues outside the GI tract can also cause diarrhea, which is commonly seen in otitis media, pharyngitis, pneumonia, urinary tract infection and skin infection. (3) Disorders of intestinal flora caused by misuse of antibiotics: long-term application of a large number of broad-spectrum antibiotics, such as chloramphenicol, kanamycin, gentamicin, ampicillin, various cephalosporins, especially the use of two or more. 3, digestive disorders (1) dietary factors. (2) Intolerance to carbohydrates. (3) Food allergy. (4) Drug effects. (5) Other factors: such as unclean environment, too little outdoor activities, sudden changes in lifestyle, sudden changes in external climate (called “wind, cold, summer, wet diarrhea” in Chinese medicine), etc. are also likely to cause diarrhea in infants.