M. Bouchoucha () • A. Faye • M. Arsac Digestive Physiology Laboratory Broussais Hospital University of Paris V 96 Rue Didot, 75014 Paris, France E-mail: michel.bouchoucha@brs.aphp.fr M. Bouchoucha Human Nutrition Research Center Avicenne Hospital Bobigny, France G. Devroede Department of Surgery CHU Sherbrooke, Québec, Canada E. Dorval Gastroenterology Service CHU Tours, France P. Arhan Physiology Service CHU de la Côte de Nacre, Caen, France order to analyze homogeneous groups, we restricted analy- sis to subjects with “normal” CTT (≤70 hours). Results Six hundred forty four IBS patients (46%) and 14 control sub- jects (9%) had CTT >70 h and were eliminated. In subjects with CTT ≤70 h, CTT did not follow a normal (Gaussian) distribution. We identified 3 different CTT clusters in healthy controls and 4 clusters in IBS patients. Even if CTT was not significantly different between clusters, each cluster was characterized by a specific pattern of segmental colonic transit. There was a marked gender difference: women had longer overall CTT values than men, both in control and IBS patient groups (p<0.001). However, female IBS patients had significantly shorter colorectal transit times than female con- trols (p<0.001), as well as faster transit than in men through the left colon and rectosigmoid area. There were no signifi- cant differences in transit time between male IBS patients and male controls with the exception of a faster rectal tran- sit in IBS patients (p<0.01). There was no association between segmental colonic transit values and sign or symp- toms comprising the Rome II criteria. Conclusions In sub- jects with CTT ≤70 h, CTT does not follow a normal distri- bution but is clustered in subgroups that can be distinguished only by measuring segmental colonic transit. Within these subgroups, there is a marked difference in transit times between IBS patients and normal subjects, suggesting that IBS patients with “normal” CTT are not “normal”. The Rome II criteria do not reflect differences in segmental tran- sit times in IBS patients with “normal” CTT. We therefore propose to evaluate segmental transit times in IBS patients with “normal” CTT, before and after treatment, in order to correctly interpretate variations in signs and symptoms. These findings have important implications in evaluating the effect of drugs on bowel function and should help define bet- ter inclusion criteria for studies evaluating new drugs for the treatment of IBS. Key words Colonic transit time • Normal values • Irritable bowel syndrome M. Bouchoucha • G. Devroede • E. Dorval • A. Faye • P. Arhan • M. Arsac Different segmental transit times in patients with irritable bowel syndrome and “normal” colonic transit time: is there a correlation with symptoms? Received: 20 May 2005 / Accepted: 16 April 2006 / Published online: 27 November 2006 ORIGINAL ARTICLE Abstract Background The Rome criteria serve as gold standard for establishing a diagnosis of irritable bowel syn- drome (IBS), but only represent a cluster of symptoms. On the other hand, measurement of colonic transit time (CTT) with radiopaque markers is a solid and more objective method to quantify functional abnormalities. The goal of this study was to investigate whether the IBS symptoms, as defined in the Rome II criteria, correspond to objective physiological parameters, i.e. CCTs. Methods The study enrolled 148 healthy control subjects and 1385 consecutive IBS patients. Transit times were measured for the whole rectocolon (overall CTT) and for 3 segments (right colon, left colon, rectosigmoid area); segmental distribution of markers and diffusion coefficients were also assessed. In Tech Coloproctol (2006) 10:287–296 DOI 10.1007/s10151-006-0295-9