Aim:

More insight in pathogenesis of IBS and IBD. Samples are collected in context of an European research project.

Methods:

Sample collection in healthy subjects, IBD and IBS patients:

• biopsy of rectum and colon descendens
• blood sample collection
• collection of sample of nasal mucosa
• feces collection
• questionnaires
• rectal barostat sensitivity measurement
• transit measurement of colon
• MR scan of brain

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)