The symptoms you relate are not limited to celiac disease. However, they most definitely point at gluten sensitivity as a root cause.

The intestines release a protein called zonulin in the presence of certain harmful antigens. Generally these antigens thrive on sweet tasting foods. Zonulin causes the intestine walls to become porous, and release undigested food into the bloodstream. The digestive immune system recognizes these antigens by their protein sequences. Grassy grains contain the same protein sequences, so grassy grains cause the same porosity reaction.

Any chemical in the digestive lumen which passes into the bloodstream can be causing your symptoms, and the causes are still 1) harmful antigens, and 2) grassy grains, in the digestive tract. When the body perceives a threat from a particular antigen it creates antibodies. The antibodies attack the antigen and attack the tissue which the antigen is threatening. The tests you have already taken, and the remaining tests you could take, all test for the presence of these antibodies.

If the antigen which is causing your problems 1) is not part of a grassy grain, but is facilitated by a grassy grain, or 2) is causing damage without eliciting an immune reaction, no test for antibodies will ever detect the fact that sugar and grassy grains are causing your problems. And medical science will never be able to test for these problems.

The only way you can test for these causes is to stop ingesting sweet tasting substances and grassy grains for 3 weeks. See what happens.