Combined MRI, high-resolution manometry and a randomised trial of bisacodyl versus hyoscine show the significance of an enlarged colon in constipation: the RECLAIM study
Wilkinson-Smith V., Scott M., Menys A., Wiklendt L., Marciani L., Atkinson D., Sansone S., Zdanaviciene A., Coupland C., Knowles CH., Dinning P., Taylor SA., Gowland P., Hoad CL., Corsetti M., Spiller RC.
Background Colonic motility in constipation can be assessed non-invasively using MRI. Objective To compare MRI with high-resolution colonic manometry (HRCM) for predicting treatment response. Design Part 1: 44 healthy volunteers (HVs), 43 patients with irritable bowel syndrome with constipation (IBS-C) and 37 with functional constipation (FC) completed stool diaries and questionnaires and underwent oral macrogol (500-1000 mL) challenge. Whole gut transit time (WGTT), segmental colonic volumes (CV), MRI-derived Motility Index and chyme movement by 'tagging' were assessed using MRI and time to defecation after macrogol recorded. Left colonic HRCM was recorded before and after a 700 kcal meal. Patients then proceeded to Part 2: a randomised cross-over study of 10-days bisacodyl 10 mg daily versus hyoscine 20 mg three times per day, assessing daily pain and constipation. Results Part 1: Total CVs median (range) were significantly greater in IBS-C (776 (595-1033)) and FC (802 (633-951)) vs HV (645 (467-780)), p<0.001. Patients also had longer WGTT and delayed evacuation after macrogol. IBS-C patients showed significantly reduced tagging index and less propagated pressure wave (PPW) activity during HRCM versus HV. Compared with FC, IBS-C patients were more anxious and reported more pain. Abnormally large colons predicted significantly delayed evacuation after macrogol challenge (p<0.02), impaired manometric meal response and reduced pain with bisacodyl (p<0.05). Part 2: Bisacodyl compared with hyoscine increased bowel movements but caused more pain in both groups (p<0.03). Conclusion An abnormally large colon is an important feature in constipation which predicts impaired manometric response to feeding and treatment responses. HRCM shows that IBS-C patients have reduced PPW activity. Trial registration number The study was preregistered on ClinicalTrials.gov, Reference: NCT03226145.