Colonic response to laxative ingestion as assessed by MRI differs in constipated irritable bowel syndrome compared to functional constipation

Lam, C.; Chaddock, G.; Marciani, L.; Costigan, C.; Paul, J.; Cox, E.; Hoad, Caroline; Menys, A.; Pritchard, Susan E.; Garsed, K.; Taylor, S.; Atkinson, D.; Gowland, Penny A.; Spiller, Robin C.

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®. 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® 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 < 0.01 and greater ascending colon volume (AC), 314 (101) mL vs 226 (71) mL in IBS-C, p < 0.01. FC motility index was lower at 0.055 (0.044) compared to IBS-C, 0.107 (0.070), p < 0.01. Time to first bowel movement following ingestion of Moviprep® was greater for FC, being 295 (116–526) min, compared to IBS-C at 84 (49–111) min, p < 0.01, and correlated with AC volume 2 h after Moviprep®, r = 0.44, p < 0.01. Using a cut-off >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.

Citation

Lam, C., Chaddock, G., Marciani, L., Costigan, C., Paul, J., Cox, E., Hoad, C., Menys, A., Pritchard, S. E., Garsed, K., Taylor, S., Atkinson, D., Gowland, P. A., & Spiller, R. C. (2016). Colonic response to laxative ingestion as assessed by MRI differs in constipated irritable bowel syndrome compared to functional constipation. Neurogastroenterology and Motility, 28(6), https://doi.org/10.1111/nmo.12784

• Journal Article Type: Article
• Acceptance Date: Nov 18, 2015
• Online Publication Date: Feb 12, 2016
• Publication Date: Jun 1, 2016
• Deposit Date: Jan 3, 2017
• Publicly Available Date: Jan 3, 2017
• Journal: Neurogastroenterology and Motility
• Print ISSN: 1350-1925
• Electronic ISSN: 1365-2982
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 6
• DOI: https://doi.org/10.1111/nmo.12784
• Public URL: https://nottingham-repository.worktribe.com/output/787154
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1111/nmo.12784/abstract;
• Contract Date: Jan 3, 2017