Fig. 1.

Respondent identification.

^aDefined as respondents who self-reported a diagnosis of IBS-D by a physician and reported diarrhea as the predominant bowel symptom.

^bDefined as respondents who reported symptoms consistent with the Rome II criteria for an IBS-D diagnosis but did not self-report a diagnosis of IBS-D by a physician. Abbreviations: IBS-D irritable bowel syndrome with diarrhea