- Had to fulfill the following criteria (IBS questionnaire) during the last 3 months prior to study entry: abdominal discomfort or pain present during at least 3 weeks in the last 3 months, and at least two of the following: abdominal discomfort or pain gets better or stops after a bowel movement; change in bowel movement frequency when the abdominal discomfort or pain starts; change in bowel movement consistency when the abdominal discomfort or pain starts