Dear Mom, The answer to your question depends on what kind of digestion problems your little guy is experiencing. If the problem is fussiness, try a milk-based 'partially digested' formula....Nestle Good Start would be appropriate. I would suggest you start with smaller volumes of milk until your baby is tolerating it. Expect a change in the quality of his stool --- it will become a peanut butter texture. A true food allergy to milk is typically associated with hives, diarrhea, vomiting, and poor weight gain. I would suggest you chat with your physician further about formula choices. Dr Cathryn