What I find is that most people understand the gluten free thing. Gluten intolerance as a term is becoming much more widely known and people are coming to some sort of understanding. But then tell them that you cannot eat dairy, and they assume you are lactose intolerant.
And I get that. In fact, somewhere around 50% of diagnosed celiacs are lactose intolerant, at least when they are diagnosed. The enzyme that breaks down lactose, lactase, is produced at the tips of the villi. And when the villi are destroyed because of undiagnosed celiac disease, lactose intolerance usually follows. After a person has been following the gluten free diet for a few months to a year, they, theoretically, should be able to eat dairy products again.
This has not been the case for me. My doctor and I are in discussions about whether I'm lactose intolerant, casein intolerant(which is the protein found in cow's milk), or just plain allergic to dairy. We've pretty much ruled out lactose intolerance, but it would kind of be nice to know. Dairy gives me reflux horribly, as does my other allergy: egg whites.
The casein protein in dairy is similar in structure to gluten, so it's quite possible that I'm intolerant to it. It seems that once you have a food that you cannot eat, others follow. When I initially started the gluten free diet, I thought it was just gluten. I thought that somehow, I'd gotten off easy. Yeah, right! A few months later, I was feeling better, but still having some stomach pains and nausea. Narrowed it down to dairy... then I ate a gluten free pizza with soy cheese and I was sick again. So, soy seems to be making the list, too.
That would be the three, the classic celiac three. No gluten, dairy or soy. At this point, I'm not sure which is harder to stay free from.