I wanted to share a great new study that was recently published by the American Journal of Gastroenterology, entitled "Gluten Causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial."
Link to the study: http://www.ncbi.nlm.nih.gov/pubmed/21224837
To sum up the study:
The participants used in the study were people that had been diagnosed with IBS, tested negative for Celiac disease, and were able to control their symptoms through the maintaining of a gluten-free diet. For six weeks, participants were either given a gluten-containing diet, or a gluten-free diet. What was found was that the majority of participants who received a gluten-containing diet experienced a recurrence of IBS symptoms. In conclusion, this study demonstrated that for some individuals, non-celiac gluten intolerance can indeed cause IBS.
Dr. Stephen Wangen (based out of Seattle) has posted a lot of helpful information on this connection between IBS and gluten-intolerances on his website (IBS Treatment Center) and his blog (http://ibstreatmentcenter.blogspot.com/).