Sorry- had to go make dinner.
My 'allergy' (not sure if allergy or intolerance, different books suggest different things) works like this, sounds like your lo has the same.
I have an amount of dairy I can tolerate- for example, i can have milk in my tea but ONLY a drizzle, and then only skimmed. Or I could have a yoghurt. But that's it for a day. If I overload my intake (the exact amount varies, stress and health seem to be factors and it is very much a cumulative thing) I get the most terrible stomach pains (not dissimilair from labour pains), diarrhoea and headaches. Even a tiny bit too much dairy also brings on absences very much like the minor epilepsy attacks.
If I eat cheese however- don't know why this is- my mouth immediately ulcerates and swells. Stronger cheeses are worse, so Stilton would be a never never, despite me loving it. The same strong reaction happens with fromage frais, worse if full fat.
Apparently as a baby I screamed until I was weaned, they thought it was colic. Then I was aware of the absences but that was it until I went veggie, then I started to get very ill. The whole thing came on fully when I became pg with my first and has never left me.
it's a real pain, although having my 1st and 3rd ds's the same makes me feel more normal. We eat alopro soya yoghurts (they were practically weaned onto them), we also used a lot of baby organix banana cereal. On bread we use FreeFrom spread as it is the only one I found with taste. other than that, we make it up as we go. I do find we eat healthily, as we don't really do sauces (so many have cream) and we eat a lot of fish to make up for the cheese protein. We also eat beans and pulses, simply because if you chuck them in a pan with tinned toms, herbs and frozen veg you've a decent meal in the time it takes to make a cheese toastie.
When I first started to get this, it was virtually unknown. Now everywhere stocks dairy free, Sainsburys and Holland and Barratt are particularly good though.