Growing evidence points to irritable bowel syndrome physiologically as a disease of the enteric nervous system characterised by hypermotility. The aim of this study was to investigate the action of pinaverium bromide a calcium channel blocker acting selectively on the gastrointestinal tract on basal and post-prandial recto-anal motility of 40 irritable bowel syndrome patients in a random, double blind and placebo controlled trial.
Pinaverium bromide (50 mg) or placebo was taken orally t.i.d. with food. Myoelectrical and mechanical activities of the rectum and the internal anal sphincter were recorded before treatment for 2 h in the fasting state and for an additional 2 h post-prandial.
Post-prandial rectal spike amplitude and frequency as well as the spontaneous recto-anal inhibitory reflex frequency decreased after pinaverium bromide (P < 0.01) but not after placebo.
These results suggest that the calcium channel blockers acting selectively on the gastrointestinal tract may have a therapeutic role in patients with irritable bowel syndrome.