Do you know if they ran the antigliadin (AGA) antibody tests? They generally omit them because they are not as specific to the intestinal damage seen in celiac disease as the newer anti-tTG test, but a positive antigliadin antibody test can indicate a degree of gluten sensitivity, even if not celiac disease.

As Glenn mentioned, up to 20% of those with biopsy proven celiac disease have negative antibodies, so it is possible to have a positive biopsy despite negative blood work.

The symptoms, arthritis and diarrhea, might very well be related to gluten or other food sensitivities. In the gluten file, you might want to read the pages on Diagnostics, gluten sensitivity vs. celiac disease, antigliadin antibodies, At Risk, food allergy, IBS, and anything else that fits. Rheumatoid arthritis is covered on the "other autoimmune disease" page.

Even if everything comes back negative, I hope you will consider a dietary trial of 3-6 months (longer the better) to see if you get symptomatic relief. Many, many people do, sometimes even when the lesser antigliadin antibodies are negative. Sometimes other food intolerances might be involved... you might want to consider IgG food allergy testing (labs can be found on the food allergy page in the gluten file.

Cara