Heh, I can sort of relate to the situation. Well, his. Currently, for what reason we don't know, but my body does not really want to tolerate any food. The few foods we've figured out I can sometimes tolerate have either never been my favorites, or gotten old quickly, so their being few foods he's willing to eat, I can understand. Lovely how that works out... because it doesn't make the problem any easier.
Also... if you do end up doing an endoscopy for Celiac's anytime soon, be careful. Maybe you have a great GI office, but mine were some of the most incompetent people I ever dealt with. They SERIOUSLY almost gave me a colonscopy, like all the way up to getting the OR type area set up for doing one instead of a colonoscopy. If I hadn't been able to tell them different, they would have so you might want to make SURE they have it all down right if he's not old enough to understand all that or wouldn't be able to or want to tell them they're wrong or something. The nurse just laughed when I said it was an endoscopy and said I seemed a little young for a colonoscopy. >.> They didn't seem terribly alarmed at their near mistake, and I found out afterward, unfortunately, it's not all that uncommon a mistake. So just be on your guard and make sure they do the right thing.

@Juniper - The reason he is on the diet is because blood tests showed that he had high allergic reactions to these foods and his body isn't processing them correctly leading to toxins in his body.  We're doing what we think is best, however, that being said, we think there's other issues and have sought a different kind of opinion today...an opinion that agrees with what we're thinking...let him eat what he wants...so that's what we're doing, slowly returning him to the foods he wanted to eat, in moderation. More definitive testing to come.  But, I completely hear what you're saying...because that's what we were saying!  Thanks!

@GinaStAubin - Yeah, it was definitely less than ideal. Our appointment was at eleven and we weren't even taken back for my IV and such to be set until like four in the afternoon, and they shooed us out of the office minutes after me waking up, only for me to discover fifteen minutes later I was having some kind of rebound reaction to the medicine that sent me to the ER the next day. >.< But that was just bad luck, I suppose. It's always good to be super careful with that stuff though. I'm sure having a sick child you might understand a lot of that, but me being older when I got sick, my parents were a little less protective of me, and a little too trusting of doctors and we've gotten into some sort of sticky situations. It's terrible that people in the medical field aren't more competent than that, but then I suppose that they're only humans and unfortunately, subject to the same possibly flaws the rest of us are, like carelessness. Anyway, I wish you the best of luck finding answers. From experience I know it's not always as easy as it should be, but hopefully things will go smoothly enough and the future will be a bit brighter for your son and your family once you figure all this out. Best wishes. <3