Pediatric diarrhea is a common pediatric disease caused by multiple pathogens and factors characterized by an increase in the number of stools and changes in stool properties, with an onset age of 2 years or less. [Explain the etiology] 1. Infectious factors: intestinal infections a fall (rotavirus), summer (E. coli). Extra-intestinal infections a pneumonia, etc., because of fever and the action of pathogenic toxins. 2, non-infectious factors: dietary factors a excessive amount or quality change of food or allergy or intolerance to food or milk components. Weather changes a cold abdomen to increase intestinal peristalsis, too hot weather to reduce the secretion of digestive juices, thirst and eating too much milk, increasing the burden on the digestive tract. Description】 1, light diarrhea: mainly gastrointestinal symptoms, loss of appetite, milk overflow or vomiting, the number of stools up to 4-5 times a day to more than 10 times, each time the amount is not much, yellow-green paste-like stool, mixed with milk flaps, foam and a small amount of mucus, stool microscopy can be seen in a large number of fat globules, no obvious systemic symptoms, occasional low fever, no weight gain or slight loss, no obvious dehydration signs and electrolyte disorders, mostly in a few days Healed within a few days. 2, heavy diarrhea: mostly intestinal infection, but also from the gradual aggravation of mild disease transformation. Acute onset, there are heavy gastrointestinal symptoms, often vomiting, severe cases can vomit coffee-like liquid, frequent diarrhea, ten to dozens of times a day. The stool is green, each time the volume is large, egg-flake soup-like or watery, there may be a small amount of mucus, stool microscopy can be seen fat globules and a small number of white blood cells. (1) Dehydration may occur, the clinical manifestation of dehydration is related to the degree of dehydration, and the nature of dehydration depends on the ratio of sodium and water lost, divided into hypotonic dehydration, isotonic dehydration, hypertonic dehydration. (2) Electrolyte disorders, hypokalemia (often manifesting abdominal distension, hypotonia of the extremities), hyponatremia and hypomagnesemia (may manifest hand and foot seizures or convulsions). (3) metabolic acidosis, bright red around the lips, deep and fast breathing (under 6 months of age, respiratory changes are not obvious). 3, long-term diarrhea can lead to malnutrition and multivitamin deficiency, and susceptible to complications such as urinary tract infections. 【Introduction of treatment】 1, light diarrhea (1) treatment of extra-intestinal foci of infection (2) regulation of diet (3) symptomatic treatment (4) oral rehydration therapy 2, heavy diarrhea (1) control of infection. (2) diet therapy: vomiting and diarrhea serious people give fasting 6 ~ 12h. (3) liquid therapy: according to the degree and nature of dehydration available oral rehydration fluid or choose different tension of the liquid and the appropriate amount of treatment, the principle of salt first and then sugar, first crystal and then gum, first fast and then slow, see urine supplementation of potassium. (4) symptomatic treatment: physical cooling or drug antipyretic for high fever, abdominal distension is serious, in addition to the appropriate amount of potassium supplementation, the use of anal canal exhaust, etc. 3, liquid therapy oral rehydration: for moderate dehydration without severe vomiting, the cumulative loss according to mild dehydration 50ml/kg, moderate dehydration 80~100ml/kg feeding, in 4~6h feeding, continued loss according to the number and amount of bowel movements. If vomiting, stop feeding for 10 minutes, and feed 5ml every 2~3 minutes. Special instructions】 1. Children should drink water as usual during the period of ORS liquid to prevent hypernatremia; if the child’s eyelids appear edema, stop taking ORS liquid and use plain water instead; newborns or renal insufficiency, shock and obvious abdominal distension ORS fluid should not be used. 2. Intravenous rehydration: quantitative, qualitative and rapid.