• Efficiency of inhibitory pain modulation, comparing patients with IBS or quiescent IBD [ Time Frame: January 31, 2020 ]
  Measured with Conditioned Pain Modulation test. Two inflatable pressure cuffs are secured around the caffs of subjects and then inflated. Pressure pain detection threshold (PDT) and pressure pain tolerance (PTT) are assessed on a subject's dominant leg. PDT is the first sensation of pain and PTT is defined as the point a subject no longer want the cuff to inflate. A VAS device allows participants to report their pain levels by moving a sliding button along a continuous line between two endpoints (0=no pain to 10=worst pain imaginable). After a second baseline measure on the non-dominant leg CPM is assessed: the cuff on the non-dominant leg is inflated to 70% of the subject's PTT, then after 15 seconds the cuff on the dominant leg is inflated. If pain modulation is achieved, the subject will show increased threshold and tolerance levels during CPM. The CPM-effect is defined as the difference between baseline and conditioning measurements of both PDT and PTT.
• Contribution of socio-demographic, clinical and psychosocial factors to the efficiency of inhibitory pain modulation [ Time Frame: January 31, 2020 ]
  Measured with a range of questionnaires, i.e.: Brief Pain Inventory Short Form (BPI), painDETECT questionnaire, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Visceral Sensitivity Index, Pain Catastrophising Scale, Cognitive and Behavioural Response to Symptoms Questionnaire, Pain Self Efficacy Questionnaire, Chronic Pain Acceptance Questionnaire-8, and Mental Health Continuum Short-Form

• Efficiency of inhibitory pain modulation, comparing patients with IBS or quiescent IBD [ Time Frame: January 31, 2020 ]
  Measured with Conditioned Pain Modulation test
• Contribution of socio-demographic, clinical and psychosocial factors to the efficiency of inhibitory pain modulation [ Time Frame: January 31, 2020 ]
  Measured with a range of questionnaires

It remains unclear why a large proportion of people with inflammatory bowel disease (IBD) report ongoing abdominal pain during remission or why people with irritable bowel syndrome (IBS) develop abdominal pain. One theory is that people with chronic pain have somehow grown more sensitive.

It is assumed that such heightened sensitivity depends both on bottom-up processing and top-down processing. Bottom-up processing refers to information that is relayed to the brain along so-called afferent fibres. Top-down processing refers to feedback provided by the brain to lower areas along efferent fibres.

The investigators will (1) measure the capacity of people to inhibit pain through top-down processing, (2) test if the human pain experience is enhanced due to sustained activation of certain afferents, and (3) assess to what extent people are impacted by psychosocial inhibition and activation factors. Results of people with IBS in remission will be compared with the results of two groups of people with IBD (those with pain and those without) and the investigators will explore if their measurements differentiate between groups.

It is hypothesized that (1) IBS patients and IBD patients with abdominal pain will be less able to inhibit their pain compared to IBD patients without abdominal pain (2) IBS patients and IBD patients with abdominal pain will score higher on psychosocial inhibition factors and lower on psychosocial activation factors when compared to IBD patients without abdominal pain. (3) In the total cohort, laboratory measures of pain inhibition will correlate with self-reported psychosocial inhibition and activation factors. (4) IBS patients and IBD patients with abdominal pain will show more temporal summation compared to IBD patients without abdominal pain.

• Abdominal Pain
• Inflammatory Bowel Diseases
• Irritable Bowel Syndrome

General inclusion criteria:

• Aged 18 and over
• Sufficient command of written and spoken English

IBD in remission inclusion criteria:

• Proof of diagnosis of IBD (Crohn's disease or ulcerative colitis) for more than 6 months - - Clear indicators of remission: on faecal calprotectin (≤200 µg/g) or measurements of C-reactive protein (CRP; ≤10 mg/dl) within the last 3 months or as part of recruitment
• No previous episodes of acute or sub-acute obstruction

IBS inclusion criteria:

• Current diagnosis of IBS measured with Rome IV criteria
• No serious other bowel diseases

Exclusion criteria:

• Major abdominal surgery in the last 6 months, or 3 or more previous major abdominal surgeries
• Pregnancy or childbirth in the last 6 months
• Any other diagnosed medical condition that may explain abdominal pain, including but not limited to known gynaecological conditions such as endometriosis and known post-surgical adhesions
• Any diagnosed co-morbid medical conditions associated with known neuropathy, such as diabetic neuropathy, renal neuropathy, multiple sclerosis
• Use of opioids in the last week
• Use of anti-depressants used as pain medication in the last month