The University of Nottingham have been developing new, non-invasive magnetic resonance
imaging (MRI) techniques to image the bowel. Building on those studies the investigators want
to study, in healthy volunteers, the effects of purging on the colon. The investigators plan
two studies using their novel MRI techniques in healthy volunteers to demonstrate how doses
of a preparation designed to clean the bowel alters small and large bowel water content and
transit. The investigators will also define the changes induced in colonic microbiota and how
these are linked to changes in transit and the structure of colonic contents. This
experimental model is comparable to an episode of acute diarrhea, therefore this study will
also improve their understanding of the effects of diarrhea on bowel physiology.
Following from the above study, the investigators would like to extend this study on patients
who have functional constipation and previously have not responded to conventional laxatives.