Dear Dr. K: I tested negative for celiac disease and I’m not allergic to wheat, but I feel better when I avoid gluten. Why?

Your question is a good one in a specific sense and in a global one.

It is reliable maxim that the feedback your body gives you is a more sensitive crucible for problems than any medical test. If your body tells you to avoid gluten, then you should do so. 

In an effort to explore your conundrum there are several possibilities.

First of all, it is possible that you do have celiac disease and your test is falsely negative. This could be due to lack of sensitivity of the test. It could also be due to the fact that a once-positive test can become negative as a person avoids gluten, and therefore avoids the stimulus that causes a positive test.

Another possibility is that your gut flora is altered and the ingestion of gluten leads to fermentation in the gut with resultant cramps, gas and diarrhea. The most common reason for this would be an overgrowth of yeast due to antibiotics, steroids, hormones or immunosuppressive drugs.

Lastly it may be that you fall into a category of people recently reported in the American Journal of Gastroenterology. The scientists who did this research project found a moderately large group of patients who have been labeled IBS (Irritable Bowel Syndrome) who simply felt better on a gluten-free diet. The scientists concluded that gluten can cause GI symptoms by a mechanism as yet not understood.