milk allergy

my son was born with a milk allergy my pediatrician said to give him whole milk at a year.

so we introduced it slowly. 1oz mixed with almond milk then 2,3,4 and the whole thing.

so we gave him his first full bottle and he’s SCREAMING in pain. it’s been going on for an hour now, i don’t know what to do. he’s crying, smacking me everytime i try to touch his belly, or pick him up. the only thing that helps is carrying him.

we called the pediatrician and they said take him to the hospital but is that too extreme?