I experienced the same problem with my daughter,  Jessica, who is now 10 years
old.  She has never been able to tolerate cows milk (lactose free or not)
since birth.  I went to an allergist for my son, who also had this problem as
an infant and toddler, and was told there was nothing they could do except
recommend staying away from dairy products.
   My son can now drink milk,  but last year, at age 13 was diagnosed with
asthma.  It has been suggested by someone on this bulletin board that the
asthma could be caused by milk ingestion, but when my son was tested by two
different allergists at different times of his life, he only had a reaction to
environmental allergens, not milk or milk products.
    I also have an allergy to casein (a milk protein) and cannot tolerate any
milk products except butter.
      Sue