My son, now 3 1/2, was very colicky. It took me a year to figure out that
my diet was the cause of it. Around 6 mos when I tried yogurt, cheese
chips, etc, he'd break out in rashes on his neck. He had eczema on the back
of his knees and elbow joints. He was so sensitive, that even when I was
cooking mac and cheese, he'd start scratching form the vapors. Put a drop
on his skin and break out. Now, he doesn't break out anymore (though he
only gets accidents), even a trace amout, the O-U Dairy, will send him into
hyperactive/defiant mode. Although he should be old enough to tell me
what's wrong, he doesn't, and acts out instead.
For My daughter, now 16 mos, I think I started milk-free (though I loaded
up on Reeses during the pregnancy knowing I'll be off it for awhile). Now
I'm not quite sure if she's sensitive to milk. I was snacking on Pringles
and those milk-free pop tarts (even through about 11 months), when I
started to realize she has a problem with my eating corn protein. This is
bad, because Mom grows and studies corn for a living. Eliminating my corn,
we realized she's even sensitive to corn products like ascorbic and citric
acid. Which was in the instant mashed potatoes and Gerber rice that we fed
her daily. It's taking a long time to figure out her sensitivities because
I'm nursing her at the same time, and what I eat affects her. So I've been
on a spartan diet because of things that affect her, but I've found no good
milk/vitamin/mineral supplement yet. I've eliminated milk, corn and soy
protein (oils I've kept), poultry, spices, and many more. I need to wean
soon because she still has cradle cap and we need a good baseline for
introducing new foods, without my diet interferring.

Juliann, mom to:
3 yr old- gluten intol, allergic to milk, soy, peanuts, nuts, legumes,
chocolate, possibly eggs
1 yr old- allergic to corn, milk, nickel, chocolate, poultry, oats,
possibly gluten intol. and salicylate sensitive (citrus, spices, mints,
berries)