RESUMO
Background: 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. Methods: 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. Results: 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. Conclusions: 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.