The symptom variables were selleck chemical as following: abdominal pain or discomfort; hard or lumpy stools; loose or watery stools; straining during a bowel movement; having to rush to the toilet for a bowel movement; a feeling of incomplete bowel movement; passing mucus (white material) during a bowel movement; abdominal fullness, bloating, or swelling. All variables were divided into frequency and bothersomeness index assessed by a 7 point Likert scale (0 = never, 1 = almost never, 2 = seldom, 3 = sometimes, 4 = often, 5 = almost always, 6 = always). Total symptom score was defined as the sum of the symptom frequency and bothersomeness scores. The potential range of frequency or bothersomeness sum-score for all symptoms was 0 to 48, and the range of total score was 0 to 96.

All questions were related to the previous 4 weeks of changes. We also measured self-reported symptom severity using the question “How bad is the discomfort usually?” and discomfort in this question implied “pain and associated IBS symptoms”. Responses were rated as mild (“can be ignored if I don’t think about it”), moderate (“cannot be ignored, but does not affect my lifestyle”), or severe (“affects my lifestyle”). 2) IBS-QOL questionnaire Each patient also completed the IBS-QOL questionnaire initially developed by Patrick et al.21 The Korean version of this questionnaire (K-IBS-QOL) has been cross-culturally validated and used in a subsequent study by Park et al.20,22 It consists of 34 IBS-specific items with high internal consistency and reproducibility. Patients were asked to choose descriptive statements using a recall period of the previous 30 days.

21 A five-point Likert scale was used to assess the degree of QOL by the statement describing the feelings of the respondent (1 = not at all, 2 = slightly, 3 = moderately, 4 = quite a bit, 5 = extremely or a great deal). There were eight subscales: dysphoria interference with activities, body image, health worry, food avoidance, social reaction, sexual function, and relationships. Subscales are scored through simple summative scaling. All items are negatively framed with the greatest response scale equaling the worst quality of life. When scored, all items are reversed so that as the IBS-QOL score increases, quality of life increases.

All final raw scores are transformed into a 0 (poor quality of life) to 100 (maximum quality of life) scale using the following formula: Scale score = (the sum of the items – lowest possible score) / possible raw score range �� 100 This transformation converted the lowest and highest possible scores into zero and 100, respectively. Scores between these values represented the percentage of the total possible score achieved. Entinostat The IBS-QOL instrument and scoring programs have used this transformation to provide comparative data for interpretation.