nature publishing group ORIGINAL CONTRIBUTIONS INFLAMMATORY BOWEL DISEASE 1 © 2010 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY INTRODUCTION Clinicians are frequently challenged to interpret gastrointes- tinal symptoms in patients with inlammatory bowel disease (IBD) who, on the basis of conventional tests, appear to be in remission. In two separate studies, irritable bowel syndrome (IBS)-type symptoms were described in 33% of patients with ulcerative colitis (UC) and in 42–57% with Crohn ’ s disease (CD), who were in remission (1,2). How does the clinician interpret such symptoms? Do they relect the coincident occurrence of IBS or the presence of persistent, but clinically undetected, low- grade inlammation? his management dilemma is particularly problematic in CD and, especially in those with disease con- ined to the small bowel, where frequent disease monitoring is logistically diicult. here is a statistically deinable likelihood of coincidence of IBD and IBS, as both syndromes are common with prevalence rates in the developed world for IBD ranging between 0.1 and 0.2% (3) and for IBS from 9 to 12% (4,5) and both may signii- cantly impact on quality of life (QOL) (6–10). However, in the absence of an identiiable cause, or a speciic biomarker for either condition, both IBS and IBD are diagnosed clinically as being mutually exclusive. In both cases, diagnosis requires not only the presence of compatible clinical features with chronicity, but also, the exclusion of diferential diagnoses. For patients with an established diagnosis of IBD, optimal management requires that disease activity be monitored accurately and treated promptly to minimize long-term complications. he risk of unnecessary and undesirable use of corticosteroids or other durgs arises in Irritable Bowel Syndrome–Type Symptoms in Patients With Inflammatory Bowel Disease: A Real Association or Reflection of Occult Inflammation? John Keohane, MB 1 , Caitlin O’Mahony, PhD 1 , Liam O’Mahony, PhD 1 , Siobhan O’Mahony, PhD 1 , Eamonn M. Quigley, MD, FACG 1 and Fergus Shanahan, MD, FACG 1 OBJECTIVES: Do gastrointestinal symptoms in patients with inflammatory bowel disease (IBD) in apparent remission reflect the coexistence of irritable bowel syndrome (IBS) or subclinical inflammation? The aims of this study were as follows: (i) to prospectively determine the prevalence of IBS symptoms in IBD patients in remission; and (ii) to determine whether IBS symptoms correlate with levels of fecal calprotectin. METHODS: Remission was defined by physician assessment: Crohn’ s disease (CD) activity index ≤150 and ulcerative colitis disease activity index ≤3, and serum C-reactive protein < 10, while off corticosteroids or biologics. Quality of life (QOL) (by inflammatory bowel disease questionnaire), the hospital anxiety and depression scale (HAD), and fecal calprotectin were measured. RESULTS: Rome II criteria for IBS were fulfilled in 37/62 (59.7%) of CD patients and by 17/44 (38.6%) of those with ulcerative colitis (UC). However, fecal calprotectin was significantly elevated above the upper limit of normal in both IBD patient groups, indicating the presence of occult inflammation. Furthermore, calprotectin levels were significantly higher in CD and UC patients with criteria for IBS than in those without IBS-type symptoms. QOL scores were lower and HAD scores higher among UC patients with IBS symptoms in comparison to those who did not have IBS symptoms. CONCLUSIONS: IBS-like symptoms are common in patients with IBD who are thought to be in clinical remission, but abnormal calprotectin levels suggest that the mechanism in most cases is likely to be occult inflammation rather than coexistent IBS. Am J Gastroenterol advance online publication, 13 April 2010; doi:10.1038/ajg.2010.156 1 Department of Medicine, Alimentary Pharmabiotic Centre, University College Cork, National University of Ireland, Cork, Ireland. Correspondence: Fergus Shanahan, MD, FACG, Department of Medicine, Alimentary Pharmabiotic Centre, and Cork University Hospital, University College Cork, National University of Ireland, Cork, Ireland. E-mail: f.shanahan@ucc.ie Received 30 July 2009; accepted 7 January 2010