Between Celiac Disease and Irritable Bowel Syndrome.pdf

? 2009 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY nature publishing group 1587 R E V IE W CLINICAL REVIEWS INTRODUCTION  e repertoire of gastrointestinal (GI) symptoms is  nite; however, the etiologies and mechanisms underlying symp- tom generation and perception are diverse and, in many cases, unknown. Symptoms, symptom complexes, and symptom characteristics are rarely, if ever, diagnostic. Functional bowel disorders (FBD), such as irritable bowel syndrome (IBS), and functional dyspepsia (FD) are, by de nition, conditions that are accompanied by GI symptoms for which no mechanistic cause has been identi ed.  is review examines the clinical and experimental evidence exploring the putative relation- ship between gluten sensitivity (GS) and the generation of GI symptoms. It explores the hypothesis that, in a proportion of patients, GS causes FBD-like symptoms. We propose a model for investigating and understanding the induction of GI symp- toms and dysfunction by gluten in FBD and organic disease. We hypothesize that, even in the absence of fully developed celiac disease, gluten can induce symptoms similar to FBD. A better understanding of how gluten can cause symptoms in sensitive individuals will illuminate the interaction between host genotype, diet, and intestinal microbiota in generating one of the most common GI conditions. DEFINITIONS OF CELIAC DISEASE AND IRRITABLE BOWEL SYNDROME Celiac disease is a condition traditionally characterized by chronic in+ ammation of the proximal small intestine result- ing in villous atrophy and malabsorption that can develop in genetically susceptible individuals ingesting gluten, the storage proteins of wheat, barley, and rye.  e prevalence of celiac dis- ease in the United States (1) and Canada (2) is as high as 0.5 – 1 % , similar to earlier estimates outside North America (3 – 6) . In contrast to celiac disease, IBS is a clinical syndrome