Individual data and mean of absolute gall bladder emptying (cm3) induced by modified sham feeding (MSF) in controls and patients with slow transit constipation (STC). Individual data and mean of absolute gall bladder emptying (cm3) induced by modified sham feeding (MSF) in controls and patients with slow transit constipation (STC). Means are represented by horizontal bars. C Penning et al. Gut 1999;45:264-268 Copyright © BMJ Publishing Group Ltd & British Society of Gastroenterology. All rights reserved.