My DS has a milk protein allergy. The advice I have been given is that most grow out of it between 6 months and 18 months. When I was feeding breast milk I had to go off dairy for him to tolerate my milk. The other thing to consider is a high number of children who have a milk protein allergy also can't tolerate soy. I am lucky on that score as my DS can tolerate soy. We are using soy formula and a high calcium vita soy milk. The other option for formula is a prescription one as mentioned by Surprised. Things like lactose free formula and goats formula still have milk protein. I haven't explored them enough to know if there is less protein or a different form of protein which might make it easier.

When we attempt the next introduction of dairy which should be very soon we will try A2 milk. The paediatrician told us that whilst it still has milk protein that a lot of kids find the protein in this milk easier to digest and is gentler on the tummy.