Diarrhea is more common in two-month-old babies, which can easily lead to water and electrolyte disorders and is a great threat to the baby’s health. 1, the causes of diarrhea in babies include the following: (1) infectious: ① bacterial: Escherichia coli is the most common bacteria that cause diarrhea in two-month-old babies, pathogenic Escherichia coli and enterotoxic Escherichia coli are common pathogens of diarrhea in two-month-old babies. 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 two-month-old babies. (2) non-infectious: ① improper feeding or extra-intestinal infection; ② lactose intolerance; ③ malabsorption. (3) Antibiotic-associated diarrhea: It refers to diarrhea secondary to the dysbiosis of intestinal flora caused by the application of antibiotics. Most occur 5-10 days after the application of antibacterial drugs, as early as the first day of medication as late as 6 weeks after discontinuation of the onset of symptoms are mostly watery, paste-like stool, varying in severity, mild self-limiting diarrhea to disseminated colitis, severe cases can be combined with electrolyte disorders and acid-base balance imbalance, and even pseudomembranous enteritis 2, dietary therapy: mild breastfeeding infants continue to breastfeed, appropriate to limit the number of nursing or shorten each nursing The artificially fed children can be fed with equal amount of rice soup or diluted milk or other milk substitutes, and gradually overtake from rice soup, porridge, noodles, etc. to normal diet. For lactose intolerant children, add lactase to the diet or remove lactose from the diet. For allergic diarrhea, switch to hydrolyzed milk powder or amino acid milk powder if protein allergy is considered. During the diarrhea, 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. 3, control of infection: (1) for bacterial infectious diarrhea: for different pathogens, choose high efficiency broad-spectrum antibiotics to kill pathogenic bacteria while avoiding damage to other intestinal flora, in order to indirectly protect the intestinal mucosal barrier. In severe cases, three generations of cephalosporins or new types of nandrolone drugs can be used. (2) Viral enteritis: no need to use antibiotics. (3) For antibiotic-associated diarrhea: antibiotics should be discontinued, or replaced with antibiotics if the condition does not allow. 4, the application of intestinal mucosal protective agent: the role of adsorption of pathogens and toxins, maintain the absorption and secretion function of intestinal cells, so that diarrhea water reduction, but also with the intestinal mucus glycoprotein interaction, enhance its barrier effect. 5, microecological therapy: the purpose is to restore the normal intestinal flora and rebuild the natural biological barrier protection of the intestine, common bifidobacterium, Lactobacillus trituberculatus (Bifidobacterium gold), Bacillus licheniformis live bacteria (whole intestine raw), etc.