@article{discovery1483147,
            note = {Copyright {\copyright} 2016 The Authors. This is an open access article under the terms of the Creative Commons Attribution License (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/),
which permits use, distribution and reproduction in any medium, provided the original work is properly cited.},
          volume = {28},
           pages = {861--870},
          number = {6},
           month = {June},
         journal = {Neurogastroenterology \& Motility},
           title = {Colonic response to laxative ingestion as assessed by MRI differs in constipated irritable bowel syndrome compared to functional constipation},
            year = {2016},
            issn = {1365-2982},
          author = {Lam, C and Chaddock, G and Marciani, L and Costigan, C and Paul, J and Cox, E and Hoad, C and Menys, A and Pritchard, S and Garsed, K and Taylor, S and Atkinson, D and Gowland, P and Spiller, R},
        abstract = {BACKGROUND: Functional constipation (FC) and irritable bowel syndrome with constipation (IBS-C) share many symptoms but underlying mechanisms may be different. We have developed a magnetic resonance imaging (MRI) technique to measure intestinal volumes, transit, and motility in response to a laxative, Moviprep((R)) . We aim to use these biomarkers to study the pathophysiology in IBS-C and FC. METHODS: Twenty-four FC and 24 IBS-C were studied. Transit was assessed using the weighted average position score (WAPS) of five MRI marker pills, taken 24 h before MRI scanning. Following baseline scan, participants ingested 1 L of Moviprep((R)) followed by hourly scans. Magnetic resonance imaging parameters and bowel symptoms were scored from 0 to 4 h. KEY RESULTS: Weighted average position score for FC was 3.6 (2.5-4.2), significantly greater than IBS-C at 2.0 (1.5-3.2), p = 0.01, indicating slower transit for FC. Functional constipation showed greater fasting small bowel water content, 83 (63-142) mL vs 39 (15-70) mL in IBS-C, p {\ensuremath{<}} 0.01 and greater ascending colon volume (AC), 314 (101) mL vs 226 (71) mL in IBS-C, p {\ensuremath{<}} 0.01. FC motility index was lower at 0.055 (0.044) compared to IBS-C, 0.107 (0.070), p {\ensuremath{<}} 0.01. Time to first bowel movement following ingestion of Moviprep((R)) was greater for FC, being 295 (116-526) min, compared to IBS-C at 84 (49-111) min, p {\ensuremath{<}} 0.01, and correlated with AC volume 2 h after Moviprep((R)) , r = 0.44, p {\ensuremath{<}} 0.01. Using a cut-off {\ensuremath{>}}230 min distinguishes FC from IBS-C with low sensitivity of 55\% but high specificity of 95\%. CONCLUSION \& INFERENCES: Our objective MRI biomarkers allow a distinction between FC and IBS-C.},
             url = {http://dx.doi.org/10.1111/nmo.12784},
        keywords = {colon, functional constipation, irritable bowel syndrome with constipation, laxative, motility}
}