Dr. Peter Green, M.D. in his book Celiac Disease, A Hidden Epidemic, calls celiac disease the most under-diagnosed autoimmune disease. It is an intestinal disease where the lining of the intestines inflame, rupture (at the surface), and even bleed. It is typically thought to be a reaction from the ingestion of wheat and dairy products; Dr. Green is convinced of this.
It is what many thought I had when I was young as I had all of the symptoms, yet did not have the allergies to confirm this. In his book, he recommends potatoes to sufferers, “Patients who are very ill should eat a few safe and simple foods. This may include rice, baked potatoes…” This is very typical of the treatment that was suggested when I was ill.
When my diet was wheat and dairy free, the problems persisted. Now that nightshades are eliminated from my diet, all of the symptoms of Celiac disease are gone. It may very well be that when the intestines are irritated from nightshades, that they are no longer able to digest wheat and diary, as they are large proteins. This may be the reason for the misdiagnosis in many people. Nightshade elimination is an easy test for suffers of Celiac disease, and should be a standard first recommendation for elimination of possible causes.
Nightshades are certainly not the cause of Celiac’s Disease, but they can exacerbate symptoms. It may be the case that people who are on a gluten free diet ingest high quantities of nightshades since they are avoiding many staple foods. This high ingestion may continuously disrupt they already sensitive bowel, and prevent any possible healing that the body might be capable of.
 Celicac Disease, AHidden Epidemic, Peter Green, M.D., p.173 and p.241