Revalidation of description of constipation in terms of recall bias and visual scale analog questionnaire

Abstract

Background and Aim: The present study was designed to identify a cut-off value to define subjective and relatively objective criteria of constipation using the visual scale analog questionnaire (VSAQ) in healthy subjects. In addition, the importance of recall bias when evaluating constipation was investigated by repeating the questionnaire and ensuring the subjects maintained diaries.