Validity and reliability of the Japanese versions of cognitive and behavioral scales for irritable bowel syndrome.

This study confirmed the reliability and validity of the 23-item version of the CS-FBS-J and the 18-item version of the IBS-BRQ-J with the deletion of items with low factor loadings. Regarding the IBS-BRQ-J, two factor structures were confirmed (factor 1: behavior obsessed with abdominal symptoms, factor 2: avoidance of abdominal symptoms and associated difficulties) although the model fit of the structure needs further study.