IBS is a "new" thing and might have more to do with leaky gut from our Western diet than anything!
They recently did away with the Reticulin antibody for CD, which is stupid! You might still be able to find a lab and a gastroenterologist who would order that one. Now they only do the Endomysial and Tissue Transglutaminase AB's. They sometimes do Gliadin AB's.
I would definitely see Shapiro, if I were you. If you have MG, you don't want to "wait and see." He might even redo the celiac AB's. If you're northern european in ancestry, the chance of you having CD is very high. See if your primary doc can refer you to him.
I have to wonder what your vitamin d and other vitamins are up to (or rather, down to).
I'll PM you and show you how it works.
Annie