Aaahhhh I don't know what to do with my husband's family. I just found out that every time Little Man has been at his great grandma's he's been getting lactose free milk...not dairy free milk. Lactose free milk still has casein, which is what I'm pretty sure he has issues with. He had diarrhea pretty much the whole time he was going to her house, but I thought it was from the dog food he was playing in that contains gluten. They don't believe he actually has a real problem since we haven't gotten a diagnosis yet (because we haven't been able to go to the dr since he was 6 months old).
After we get a proper diagnosis, assuming he is actually allergic to milk, I still don't think I'll be letting him stay here without me for a while and only let him eat and drink things I bring. I know they'll think I'm a bitch, but I'm not going to trust they're giving him the right stuff after they flat out refused to.
To their benefit, they have been making sure everything is gluten free. I'm not sure why they believe that one but not the dairy intolerance, even though that's the one he reacts the worst to.