Four and a half year old babies who have diarrhea, first to identify and analyze the cause, need to check the stool routine occult blood, rotavirus is normal. If there is bacterial infection or viral infection in the stool, while actively applying anti-viral and anti-bacterial drugs, oral probiotics can be taken together to regulate the intestinal function. If the baby’s stool examination is fine and it is purely indigestion, you need to pay attention to the baby’s reasonable diet, don’t eat too much greasy and indigestible food, and at the same time take oral probiotics to regulate it. A few babies may be caused by allergies, avoid contact with allergic foods.