Lactose intolerance
Lactose intolerance is an adverse reaction to cow's milk.
People may suffer this adverse reaction because the protein component of milk is not tolerated or because the milk sugar, called lactose, is not tolerated.
If a person is unsure which component of milk they do not tolerate, then it is preferable to avoid both and to follow a milk-free diet.
This would mean avoiding not only cow's milk, but all other animal milks such as sheep, goat and buffalo etc.