Celiac disease, being an immune system related disorder of the small intestine, generally responds well to a gluten-free diet since such a diet minimises the challenge to the immune system. As a result, the antibodies used for establishing the diagnosis may fall gradually to much lower levels if the diet is strictly gluten-free. In fact, these antibodies may even disappear from the system altogether. Many physicians monitor the levels of antibodies over time as a surrogate marker of diet compliance.
Another method commonly employed is an upper endoscopy with biopsies of the duodenal wall to look for clues of active inflammation. This method also has the advantage of excluding other issues in the duodenum for the diarrhoea.
If diarrhoea persists and there are no detectable antibodies in the serum and upper endoscopy did not show worsening changes related to celiac disease, one has to seek for other problems including lymphoma developing in the small bowel.
