Newborns ate montelukast after stool or water can be seen in infectious diarrhea disease, lactose intolerance, milk protein allergy, etc., the intervention needs to be based on the cause of the reasonable intervention, such as lactose intolerance need to use lactase and other treatments. 1. Infectious diarrhea disease: such as bacterial infections caused by diarrhea, complete routine stool examination can be seen in leukocytes, montelukast is the intestinal mucosal protective agent, such children only oral the drug is symptomatic treatment, the cause of the disease has not been controlled, the therapeutic effect may not be good, the treatment can be based on the allergy to select the application of antimicrobial drugs, such as cephalosporin and other anti-infective. 2. Lactose intolerance: this kind of baby is mostly due to the intestinal lactase enzyme insufficiency, after eating lactose-containing dairy products, watery stools can occur, this kind of children can affect the growth and development of the seriousness of the disease, only the use of montelukast for treatment may not be good enough, need to be taken orally to lactase for the treatment, and if necessary, need to be adjusted to the guidance of the physician to lactose-free milk powder for feeding. 3. milk protein allergy: can also appear watery stool phenomenon, some babies can appear blood stool, only the use of montelukast is not good, such babies such as breastfeeding their mothers need to avoid eating protein foods, the effect is not good, or the use of formula breastfeeding need to be adjusted under the guidance of the physician to hydrolyzed protein milk powder for feeding. It is recommended that newborns with watery stools actively consult a specialist for treatment. The above medications should be used under the supervision of a physician.