Have you ever been tested for celiac disease? I was also told for decades that I had IBS....turned out to be celiac. I was finally diagnosed at the age of 52, but I've probably had it most of my life.
The really unfortunate thing about
not being diagnosed properly is that the only treatment for celiac is the gluten free diet. And untreated celiac disease can lead to other autoimmune diseases: www.umm.edu/news/releases/zonulin.htm
Which may explain why I now have so many darn AI diseases!! :(
You may want to ask your doctor about
the possibility of celiac disease. If you do get tested and the tests come back negative (there are frequent false negatives in both the blood work and biopsies for celiac), then you can test yourself by going gluten free for a week or two then going back on gluten. If you feel better on the gluten free diet and worse when you go back to gluten, then you know!