How can i know if my baby has milk allergy? no vomiting no reflu only severe colic, she is 3 months now.

Rare but possible Dx: True milk allergy would produce 24/7 sx & could produces frothy pink stools with blood. Intolerance to a milk component may produce less intense sx. Use of a special hypoallergenic formula like ready to feed alumentum for 4-5 days would wash out the milk & calm baby if this were the issue.If baby is not noticeably better, other factors are involved.