RESUMEN
This study aimed to evaluate psychometric characteristics [diagnostic validity and reliability] of quality of life questionnaire in irritable bowel syndrome [IBS-QOL] which is a popular inter-cultural measure. According to ROME II criteria 126 patients were included by the caring physician in Alzahra and Noor hospital clinics in Isfahan, Iran. Results: Eight scales of the questionnaire and total quality of life measure showed good internal reliability [Cronbach alpha=0.93 for the whole questionnaire, 0.88 for dysphoria, 0.67 for activities interference, 0.72 for body image, 0.57 for health worry, 0.57 for food abstinence, 0.71 for social reaction, 0.76 for sexual worry, 0.62 for interpersonal relations]. The validity was measured against another quality of life questionnaire [IBS-QOL-36] and a significant correlation was found [r=0.61. p<0.01]. To evaluate diagnostic accuracy 40 patients were compared with 40 healthy subjects. Except for body image scale other parts of questionnaire and the global quality of life were significantly different between these two groups [p<0.05]. Generally, Farsi version of IBS-QOL questionnaire was found to be a valid and reliable mean to study patients with irritable bowel syndrome