Background: The utility of current diagnostic criteria for dyspepsia and irritable bowel syndrome (IBS) in clinical practice is largely unknown. We aimed to compare the diagnostic value of different definitions and questionnaires in a population.
Methods: The Abdominal Symptom Questionnaire (ASQ) was mailed to a representative sample (n = 1506, 20-87 years old), and every fifth person (n = 302) concomitantly received the Bowel Disease Questionnaire (BDQ). The diagnostic agreement for dyspepsia and for IBS, defined in accordance with the Manning and the modified Rome criteria and a new simple definition, was analysed.
Results: In the ASQ the agreement on the IBS status for the three IBS definitions was > or = 88%, and in the BDQ > or = 93%. Agreement for the three definitions on the two questionnaires was > or = 88% regardless of which definition of IBS was applied. Agreement between questionnaires was similar (88%) for dyspepsia. For both IBS and dyspepsia the kappa coefficients indicated moderate to substantial concordance. 'Pain or discomfort' did not cover all linguistic aspects of dyspepsia. Prevalence rates of dyspepsia were comparable in the ASQ and BSQ, whereas higher prevalences of IBS with the ASQ was related to the cutoff levels for reporting abdominal pain or discomfort.
Conclusion: It is possible to identify IBS more simply by self-report questionnaires.