Validation of the Korean version of visual analogue scale for irritable bowel syndrome questionnaire for assessment of defecation pattern changes

PURPOSE: Patients often complain of change of defecation pattern and it is necessary to quantify their symptoms. To quantify symptoms, use of questionnaire is ideal, so we adopted a simple and easily writable visual analogue scale for irritable bowel syndrome questionnaire (VAS-IBS). The aim of this study was to develop and validate the Korean version of VAS-IBS questionnaire (Korean VAS-IBS) that can adequately reflect the defecation pattern. METHODS: This study translated English VAS-IBS into Korean using the forward-and-back translation method. Korean VAS-IBS was performed on 30 patients, who visited the outpatient clinic and had no possibility of special defecation pattern. Detailed past medical history and Bristol stool chart was added to the questionnaire. The survey was conducted twice, and the median interval between the 2 surveys was 10 days (8–11 days). Cronbach α for internal consistency reliability and intraclass correlation coefficients for test-retest reliability were analyzed. RESULTS: Korean VAS-IBS achieved acceptable homogeneity with a Cronbach α coefficient of 0.66–0.79 showing adequate internal consistency reliability. In addition, intraclass correlation coefficients showed significant test-retest reliability with 0.46–0.80 except for the question assessing the “perception of psychological wellbeing.” CONCLUSION: The Korean VAS-IBS is a valid and reliable questionnaire for the measurement of the symptoms of defecation pattern changes.