On the basis of 4 adult population samples subsequently gathered into one sample of 567 healthy subjects, we determined: (1) the annual prevalence of symptoms suggestive of intestinal functional disorders (30.5 per cent); (2) the elements which prompted subjects with symptoms to request medical attention (we found that the request was significantly correlated with the duration of pain, the intensity and chronicity of constipation, the number of symptoms and the triggering of disorders by stress), and (3) an estimate of the "cost" of intestinal functional disorders.