Diarrhea with watery stools suggests diarrhea, and watery stools are mostly caused by acute diarrhea, and the common causes include infectious and non-infectious, where the causes of infectious diarrhea include viral, bacterial and other pathogenic infections; the causes of non-infectious diarrhea mainly include improper diet, allergen stimulation, lactose intolerance, etc.; the treatment of watery stools in diarrhea firstly requires active hydration to maintain water-electrolyte balance, preferably oral rehydration salts, but if dehydration is severe or there are vomiting symptoms, intravenous fluids are also needed to replenish water and maintain blood volume stability. Infectious diarrhea caused by bacteria needs to be treated with antibacterial drugs; infectious diarrhea caused by viruses is mostly watery stools and does not require antiviral drugs for etiologic treatment. In the case of non-infectious diarrhea, the cause of diarrhea should be clarified and dietary care should be done to avoid allergic foods and lactose-intolerant people can use lactose-free formula. Therefore, once diarrhea occurs with watery stools and a small number of times, drink more water or take oral rehydration salts to replenish water, observe the diarrhea, if the number of times is high, infusion therapy is available if necessary, and stool routine and stool culture examination should be improved to further clarify the cause of diarrhea, and further treatment should be done according to the cause.