<<My son is the same way. He is intolerant to the protein. He actually has
a condition that has been
diagnosed that causes him to be "allergic" (for lack of a better term
although it's not a histimine response reaction) to milk.>>

The same goes for my 3 yr old.  She was tested and came back negative.  She
is sensitive to milk.  She breaks out in a face rash then has cramps and
diarrhea.  We just avoid it for the most part.  Since she loves chocolate
that is the one indulgence that she gets every once in a while.  My husband
and I decided we would wait until she is old enough to verbalize how her
reactions feel to her, then let her decide.  Until then we are just avoiding
it as much as possible.  There are plenty of other things for her to eat.
Besides at this age they are so picky about what they will eat that getting
them to try anything new is a losing battle!  Hope this helps.