Manometric parameters characterizing anal sphincter function are not correlated with the predominant bowel movement pattern in IBS. The features of PFD are significantly more frequent in all subgroups of IBS patients than in controls, suggesting that, in general, IBS patients show changes in the mobility of the pelvic floor. Hypersensitivity to rectal distension is commonly observed in IBS, but it does not seem to be a highly specific marker of the disorder.