Published online May 7, 2014. doi: 10.3748/wjg.v20.i17.5000
Revised: December 20, 2013
Accepted: January 3, 2014
Published online: May 7, 2014
AIM: To ascertain whether caecal pH is different in patients with irritable bowel syndrome (IBS), whose primary symptoms are bloating and distension, to healthy controls.
METHODS: Motility and pH data were reviewed from 16 patients with Rome III defined IBS and 16 healthy controls, who had undergone a wireless motility capsule (WMC) study using a standardized protocol. Motility measures were anchored around known anatomical landmarks as identified by compartmental pH changes. Sixty-minute epochs were used to quantify antral, duodenal, ileal, caecal and distal colonic contractility. The maximum and minimum pH was measured either side of the ileo-caecal junction.
RESULTS: No differences were seen in motility parameters, compartmental transit times or maximal ileal pH between the two groups. Caecal pH was significantly lower in patients compared to controls (5.12 ± 0.05 vs 6.16 ± 0.15, P < 0.0001). The ileal:caecal Δchange was greater in patients than controls (-2.63 ± 0.08 vs -1.42 ± 0.11, P < 0.0001). There was a significant correlation between caecal pH and right colonic contractility (r = 0.54, P = 0.002).
CONCLUSION: Patients with bloating and distension have a lower caecal pH compared to controls. The measurement of caecal pH using the WMC provides a quantifiable biomarker of fermentation potentially identifying those patients that may preferentially benefit from antibiotic or dietary interventions.
Core tip: Colonic bacterial fermentation has been implicated in the pathogenesis of irritable bowel syndrome. Hitherto, the measurement of fermentation in vivo in humans has been invasive and technically challenging. A major by product of colonic bacterial fermentation are short chain fatty acids. These short chain fatty acids act to reduce colonic pH. Herein, we demonstrate that the measurement of caecal ph using the wireless motility capsule provides a quantifiable biomarker of fermentation potentially identifying those patients with irritable bowel syndrome that may preferentially benefit from antibiotic or dietary interventions.