The authors report the main acquisitions from literature and their own experience concerning therapy of intolerance and allergy to cow's milk proteins, particularly referring to clinical gastrointestinal features. These points have been underlined: elimination diet is the most important step in therapy, even if intolerances to new aliments frequently arise (30% of cases), either when soy milk or hydrolysate formulas are used; pharmacologic agents inhibiting mediator release from the mast-cells thereby reducing gut permeability to macro-molecules (such as disodium cromoglycate) can be used as a "support" for a short period of time, but the drug can not replace the diet in the therapy; anyway, even if milk allergy may last for a long time, it is useful to test the possible acquired tolerance, beginning from the first year of life.