Assessment of functional gastrointestinal disorders using the Gastro-Questionnaire.

The purpose was to investigate the reliability and factorial structure of the Gastro-Questionnaire for the screening and psychometric measurement of functional gastrointestinal disorders (FGDs). The questionnaire contains 27 gastrointestinal symptom items drawn from the Rome-II criteria, which are rated by frequency and severity, as well as some items to exclude organic diseases. The questionnaire was administered to 259 normal participants and to 69 participants of the annual German meeting of patients with irritable bowel syndrome. Reliability was good (Cronbach's alpha for frequency and severity items: alpha = .86 and alpha = .87). Factor analysis yielded a six-factor solution explaining 60.7% of the variance. Diagnostic frequencies ranged from 32.8% to 100% for FGDs in general, from 1.3% to 76.8% for irritable bowel syndrome, and from 7.0% to 100% for functional dyspepsia, depending on samples and symptom definitions. The Gastro-Questionnaire is a very economic, reliable, and content-valid instrument for the assessment of FGDs.