Harry: I would say that it?s unlikely but I suppose it is a possibility because some people can be allergic to the protein in milk.

Mary: Well I do suffer from hay fever, but I can?t give up my milk.

Harry: Look, it is a possibility but there are also other reasons why people have difficulty with milk and that is because of the milk sugar. So you can be allergic to the milk protein because after all you are drinking cow protein, which is not the same as your protein. However it?s much more common in infants and children and usually they grow out of it, although it can persist into adult life. But the other problem, which is perhaps even commoner certainly in adults, is that people have the inability to digest lactose. We call that lactose intolerance. Lactose is the fancy name for milk sugar. So many people can?t digest the milk sugar and what happens is that the milk sugar goes down into the colon and can cause all sorts of complications like gas, colic and diarrhoea.

Mary: So would you suggest that I use skim milk?

Harry: Why don?t you try that. It may not make any difference because skim milk has also got protein and sugar, but it?s worth a try because you may even be a little intolerant of the fat in milk.

Mary: What about powdered milk?

Harry: Well you can try these various forms of milk and if they fail, you can drink soymilk, which is milk made from soya. It is widely available commercially.

Harry: Okay, thank you very much.