Neonatal diarrhea is a common disease in the neonatal period, which can easily lead to water and electrolyte disorders and is a great threat to the health of newborns. Neonatal diarrhea is divided into infectious diarrhea, non-infectious diarrhea and antibiotic-associated diarrhea. 1, infectious: infectious diarrhea can be caused by bacteria, viruses, fungi, parasites and other infections of the intestinal tract. (1) bacterial: Escherichia coli is the most common bacteria causing neonatal diarrhea, pathogenic Escherichia coli and enterotoxigenic Escherichia coli are common pathogens of neonatal diarrhea, and diarrhea caused by attacking Escherichia coli is mostly sporadic. (2) Viral: rotavirus is the most common. (3) fungal: mostly occurs after long-term application of antibiotics, with Candida albicans as the most common. (4) parasites: trichomonas, pear-shaped flagellates can cause diarrhea in newborns. 2, non-infectious: non-infectious diarrhea is mostly caused by neonatal allergy to milk protein and lactose intolerance. Newborns have immature digestive function, low acidity of gastric juice, insufficient secretion or low activity of digestive enzymes, and low tolerance to food, and if they are not fed properly, newborns will develop diarrhea. If the milk powder is not brewed at the correct concentration, if the milk powder is replaced, if sugar is added to the milk powder, if the milk is too cold or if starchy foods such as rice paste are added too early, this can easily lead to diarrhea in newborns. 3, antibiotic-related diarrhea: refers to the application of antibiotics resulting in the imbalance of intestinal flora, and secondary diarrhea. The symptoms are mostly watery, pasty stools, varying in severity, mild self-limiting diarrhea to disseminated colitis, severe cases can be combined with electrolyte disorders and acid-base imbalance, and even pseudomembranous enterocolitis.