A baby with loose watery stools but in good spirits needs treatment. The baby’s stool is thin and watery, consider the possible existence of lactose intolerance, acute enteritis, rotavirus infection and other problems, you can take general treatment, montelukast and other medications. 1. Lactose intolerance: usually occurs in babies who are mainly breastfed. Accompanied by abdominal distension, vomiting, crying and restlessness and other symptoms, can take lactase auxiliary treatment, or change the low-lactose milk powder, usually have significant improvement. 2. Acute enteritis: at this time the baby’s stool thin watery, accompanied by vomiting, fever and other symptoms, available cefixime and other antibiotics and other anti-infective treatment, at the same time can be added with montelukast to protect the gastrointestinal tract, bifidobacterium and other probiotics to regulate the bacterial flora. 3. Rotavirus infection: rotavirus infection is most common in the fall, children can have repeated eggdrop soup-like loose stools, no specific treatment, can be under the guidance of the doctor to replenish the balance of water, salt and electrolytes can be. There are other possibilities, such as protein allergy. It is recommended to actively seek medical attention, improve the examination, find the right cause, scientific treatment, the above medication should be used in accordance with medical advice.