The effects of pinaverium bromide, a non-absorbable antispasmodic agent, administered locally, on sigmoid-rectal motility was investigated in 20 patients with irritable bowel syndrome. The influence of either pinaverium (10 subjects) or placebo (10 subjects) on a neostigmine-induced increase of sigmoid pressure was assessed and compared by means of computerized electromanometry. The drug was found to counteract significantly the motor effects of neostigmine, thus appearing to be an effective compound for the treatment of functional disorders of the colon.