Hi Doris, I truely do not believe a one month baby has lactose intolerance and wonder how this Pedi came up with this dx? My first suspicion when you mention baby "vomitting" after every brfdg is an overactive let-down or hyperlactation. THe LLL Lactation Consultant Series has a great chapter on this problem. I would ask her questions such as: Does the baby make gasping sounds or choking sounds while nrsg? Does the other breast have an active leaking while baby nrsg other side? Is there a sound of mom's milk hitting an empty barrel when baby is nrsg? What has the baby's wt been? Big wt gains? What are the stools like? Are they frothy, green, lacking curds? If there is a yes to any of these quetions I would pursue hyperlactation as a dx not lactose intolerance. Ann Perry RN IBCLC