One and a half month baby water stool can be seen in infectious diarrhea, non-infectious diarrhea (such as glycogen diarrhea), the treatment needs to be based on the cause of the selection of targeted treatment, such as bacterial infections caused by diarrhea need to be anti-infective and other treatments. 1. Infectious diarrhea: it can be caused by viruses (e.g. rotavirus) or bacteria (e.g. Escherichia coli), and the clinical manifestations mentioned above can be seen, accompanied by an increase in the number of stools. Treatment requires the use of intestinal mucosal protective agents (such as montelukast) and microecological agents (such as Saccharomyces boulardii) to alleviate diarrhea symptoms, and the presence of bacterial infections requires the use of antimicrobial drugs (such as cefaclor) to fight infections and other treatments. 2. Non-infectious diarrhea: (1) Glycogenic diarrhea: mainly refers to the lack of lactase enzyme, after eating lactose can not be digested blowing according to the diarrhea, the treatment needs to go to the lactose diet, such as the use of lactose-free formula milk. (2) allergic diarrhea: diarrhea, bloody stools, etc., some babies may have eczema, treatment requires the use of hydrolyzed protein formula milk, adjust the diet. All of the above medications should be used under the guidance of a physician, and it is recommended to consult a physician as soon as possible to have the cause of the diarrhea evaluated and treated by a specialist to avoid long-term diarrhea from affecting the normal growth and development of the child.