Visceral Sensitivity in IBD (Irritable Bowel Disease) and IBS (Irritable Bowel Syndrome)

Inclusion Criteria: For group 1: IBS 1. Irritable Bowel Syndrome (IBS) (ROME III criteria) 2. No obvious organic explanation for the IBS symptoms 3. Medication which affects the gastrointestinal motility or perception should be stopped at least 24 hours before the study Group 2: active ulcerative colitis 1. diagnosis of ulcerative colitis (Confirmed by at least one sigmoidoscopy) 3. Medication which affects the gastrointestinal motility or perception should be stopped at least 24 hours before the study Group 3: ulcerative colitis in remission (3a: with IBS symptoms, 3b: without IBS symptoms) 1. diagnosis of ulcerative colitis (Confirmed by at least one sigmoidoscopy) 2. remission is confirmed by at least one sigmoidoscopy 3. Medication which affects the gastrointestinal motility or perception should be stopped at least 24 hours before the study Only for group 3a: 4. Rome III criteria for IBS Group 4: Healthy controls No abdominal (pain) complaints. Group 5: active Crohn's disease 1\. diagnosis of Crohn's disease (Confirmed by at least one sigmoidoscopy) 3. Medication which affects the gastrointestinal motility or perception should be stopped at least 24 hours before the study Group 6: Crohn's disease in remission (6a: with IBS symptoms, 6b: without IBS symptoms) 1. diagnosis of Crohn's disease (Confirmed by at least one sigmoidoscopy) 2. remission is confirmed by at least one sigmoidoscopy 3. Medication which affects the gastrointestinal motility or perception should be stopped at least 24 hours before the study Exclusion Criteria: For all groups: 1. co-morbidity: severe kidney- and/or liver disease or thyroid abnormalities and impaired clotting 2. Abdominal chirurgy (except for an uncomplicated appendectomy)