Diarrhea is the result of comparison with the usual stool pattern and frequency. If your baby’s stool changes after drinking formula, such as thin stools, more water, or an increase in the number of stools compared to before, then you should consider it diarrhea. In general, babies who drink only breast milk within four months have stools about 2-4 times a day, yellowish green in color and pasty in shape. Babies who drink formula milk have 1-2 bowel movements per day, with yellowish color and mostly formed stools. If your baby has 4-5 or more bowel movements per day, or on the contrary only once every 2-3 days, but the stool is as usual, the child has gained weight, is in good spirits, and is eating milk, then there is no need to worry. If your baby has diarrhea when drinking milk powder, the number of bowel movements is slightly more than before, the quality of the stool is thin and unformed, the stool smells bad, and serious symptoms of dehydration may appear, such as dry skin and lips, and the number of urine is less than usual, you need to send your baby to the doctor for treatment in time. Usually exclude the underlying disease, milk powder quality problems and brewing method errors, the main causes of diarrhea in babies drinking milk powder are milk protein allergy, lactose intolerance two, can be solved by the following methods: 1, lactase deficiency: If lactose intolerance caused by diarrhea, just change a can of lactose-free milk powder can, within 2-3 days the symptoms will quickly improve, some babies are temporary Some babies are temporarily lactose intolerant and will gradually get better as they grow up, but some are congenitally lactose intolerant and need to eat lactose-free formula all the time; 2. Milk protein allergy: you need to replace the milk powder with hypoallergenic milk powder, and generally the diarrhea will improve after the milk change to make it clear that the diarrhea is caused by milk protein allergy. There are many kinds of hypoallergenic milk formulas, the most commonly used of which is deeply hydrolyzed protein milk powder, such as allergies need to apply amino acid formula.