How is it diagnosed?
There are different tests for cow’s milk allergy and lactose intolerance, so it’s important that you discuss your child’s symptoms in detail with your doctor, who will decide which tests are most appropriate to get the right diagnosis.
If cow’s milk allergy is suspected, your doctor may request an allergy test such as a skin prick test or blood test, and/or advise you to put your baby on an elimination diet followed by a food challenge.
If your doctor thinks it may be lactose intolerance, he or she may request a hydrogen breath test, lactose tolerance test, milk tolerance test or stool sample. You can find out more about these different tests from NHS Choices.