Not everyone who bloats up has celiac. I do not, and yet I can't tolerate wheat, and so stay mostly GF. I can eat some things which others can't, but I went totally GF, though the naturopath didn't say I needed to do so. My doctor just treated me for IBS and didn't even think about it.
Also, do you have a hypothyroid problem? Many who do, especially those with Hashimoto's disease have a gluten intolerance. For some, dairy is a problem. I tried that first, and it was like I hadn't done anything.
There are many protein powders out there, and if you buy one, read the ingredients. I can't do much soy, so I use a whey or a hemp one. Don't spend too much money, as you may just hate the taste, and then are stuck with a lot of something.
Good luck, and yes, demand to be tested for foods, but be aware that if you don't actually have celiac, your doctor may blow you off again.
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Antoine de Saint Exupery: The Little Prince
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