KCE-16001: Diet Or Medication in Irritable bowel syndrome – DOMINO

Summary (French or Dutch)

Irritable bowel syndrome, present in up to 15% of the general population in Belgium, is one of the most prevalent conditions encountered in clinical practice (up to 5% of general practitioner consultations). Typical irritable bowel syndrome patients are middle aged and report chronic symptoms of abdominal pain and altered stool pattern, in the absence of an overt underlying cause, and with major impact on quality of life.

In these patients, there are considerable supplementary costs due to supplementary examinations (often found to be normal), a higher incidence of abdominal surgeries (appendectomy, hysterectomy and gallbladder surgery) which fail to improve the symptoms, and absence from work or impaired functioning at work. Treatment most often relies on the chronic intake of drugs, that alter bowel function, but whose efficacy is limited. This situation generates uncertainty for the treating physician and dissatisfaction for the patient, both triggering additional examinations and combination therapies and hence increased costs and important psychosocial impact for patients.

Some recent studies have shown that symptom control in irritable bowel syndrome can be obtained with a relatively simple dietary intervention (reduction of food products that are osmotically active or undergo fermentation). There are a number of obvious advantages to an easily applicable dietary intervention, including the low cost, the benefit of the patient having control over symptoms and the long-term efficacy potential.

The aim of the present study is to compare the efficacy of this diet with traditional medication therapy on symptom control in the short term, on the need for additional examinations and on health care costs in the long term. To do this, 470 irritable bowel syndrome patients will be recruited by general practitioners in Belgium and randomized to be treated with either the traditional medication or the diet, and followed for 6 months. We expect better symptom control and a diminished cost in patients who respond well to the diet.

Trial Description

A randomized controlled trial to evaluate the short-term efficacy and long-term health economic impact of a dietary intervention compared to pharmacotherapy with a musculotropic spasmolytic agent for newly diagnosed or newly treated irritable bowel syndrome in primary care. (KCE-16001)

Participants (P)

Newly diagnosed or newly treated patients with IBS (based on clinical judgement of GPs who are familiar with the Rome criteria) presenting in primary care.

Intervention (I)

Dietary intervention (based on the NICE dietary guideline for IBS, adapted to Belgian food standards and culture).

Control (C)

Spasmolytic agent, otilonium bromide (most frequently prescribed IBS drug in Belgium).

Outcome (O)

The primary outcome variable is control of IBS symptoms, the proportion of responders with the two treatment arms will be compared. A responder is defined as a patient with an improvement of 50 points or more on the IBS Symptom Severity Scale.

Trial Design

A pragmatic, prospective, multi-center, open label, parallel-group, 1:1 randomized controlled trial, 8 weeks treatment, 6 months total follow-up

Sample Size


Trial duration

24 Months


€ 2 122 474 (incl. VAT)


Closed to recruitment - in follow up


Trial team


UZ Leuven – KU Leuven

Chief Investigator

Prof Dr Jan Tack

Department of Gastroenterology and Hepatology, Leuven University Hospitals and TARGID (Translational Research Center for Gastrointestinal Disorders), University of Leuven

Trial coordinator

Florencia Carbone

Department of Gastroenterology and Hepatology, Leuven University Hospitals and TARGID (Translational Research Center for Gastrointestinal Disorders)

Trial team


Protocol Download here
Report Q3 2020
Publication Q4 2020

ClinicalTrials.gov: NCT04270487

EudraCT:  2017-003258-18


Funding scheme

Commissioning workstream 2016