 Main study parametersendpoints: The main study parameter is a change in pain reduction perception experienced and measured by the patient using VAS-scales before and after taking the chewing gum, to be recorded in a diary. Next to this a patient is asked to provide one VAS score for each completed week. Furthermore, the adequate relief will be measured every day. At the end of each week patients will also be asked from their diary whether they noticed a change in stool frequency or and experienced any side-effects. For the disease-related quality of life the IBS-QOL will be used. This questionnaire will be filled out in week 1, 4, 5, and 8. 