RESUMO
BACKGROUND: The ROME III diagnostic questionnaireforpediatric functional gastrointestinal disorders (FGIDs) is widely accepted as an essential tool for the diagnosis ofFGIDs in children and as a research tool. However, the questionnaire has not been translated into Thai. OBJECTIVE: To transpose the ROME III diagnostic questionnaire and to determine its validity and reliability in the Thai cultural setting. MATERIAL AND METHOD: The original English ROME III diagnostic questionnaire, composed of 71 items, was translated into Thai following permission from the ROME foundation. The ROME III questionnaire, Thai version was then translated back to English by a bi-lingual expert. The original English and the back-translation versions were compared and the validity was analyzed using Index ofl Item-Objective Congruence (IOC). Finally, the Thai questionnaire was tested with 50 healthy school-children aged four to 15 years old who had no serious illness. The questionnaire was answered by parents for children aged four to 10 years, and self-answered by children aged over 10 years. The reliability was evaluated by Cronbach's alpha coefficient. RESULTS: Item to item comparison between the original English and the back-translation versions valued by IOC was 0.94, which indicated high validity. The Cronbach's alpha coefficient of the overall 71 items was 0.98, which indicated high reliability. Moreover the alpha of reliability for self-report and parent-report was 0.96 and 0.97 respectively. CONCLUSION: The ROME III diagnostic questionnaire in Thai is valid and reliable for the diagnosis of FGIDs in Thai children.