Dose-dependent FODMAP Reintroduction in IBS (DORI)

Dose-dependent Individual FODMAPs (Mannitol and Fructans) Reintroduction in Patients With Irritable Bowel Syndrome

The aim of this study is to evaluate whether symptom recurrence, after successful FODMAP elimination, is dose-dependent in patients with IBS. The effect of a blinded reintroduction of FODMAP powders fructans and mannitol will be investigated in a crossover dose-escalation scheme for the identification of the eliciting dose in individual patients. The reintroduction of FODMAPs is performed after a successful elimination by the LFD.

Study Overview

• Status: Completed
• Conditions: Irritable Bowel Syndrome
• Intervention / Treatment: Other: FODMAP powder reintroduction

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Bruges, Belgium
    • AZ Sint Lucas

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
2. Use of highly effective methods of birth control; defined as those that, alone or in combination, result in low failure rate (i.e., less than 1% per year) when used consistently and correctly; such as implants, injectables, combined oral contraceptives, some IUDs, true sexual abstinence (i.e. refraining from heterosexual intercourse during the entire period of risk associated with the Trial treatment(s)) or commitment to a vasectomised partner.
3. Patients with irritable bowel syndrome according to Rome IV diagnostic criteria
4. Patients ages between 18 and 70 years old

Exclusion Criteria:

1. Participant has a history of any major psychiatric disorders (including those with a major psychosomatic element to their gastrointestinal disease), depression, alcohol or substance abuse in the last 2 years

1. Any disorder, which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol
2. Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the Trial
3. Female who is pregnant, breast-feeding or intends to become pregnant or is of child-bearing potential and not using an adequate, highly effective contraceptive
4. Participation in an interventional Trial with an investigational medicinal product (IMP) or device
5. Patients presenting with predominant symptoms of functional dyspepsia (FD) and of gastro-oesophageal reflux disease (GERD)
6. Patients following a diet interfering with the study diet in opinion of the investigator
7. Patients who already followed the low FODMAP diet under guidance of a trained dietitian without success.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Mannitol; Mannitol belongs to the group of polyols within the FODMAPs.	Other: FODMAP powder reintroduction; The FODMAP powders will be reintroduced in three different doses, each for three consecutive days.
Active Comparator: Fructans; Fructans belong to the group of oligosaccharides, specifically the fructose-oligosaccharides (FOS), within the FODMAPs.	Other: FODMAP powder reintroduction; The FODMAP powders will be reintroduced in three different doses, each for three consecutive days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dose dependency	The study aims to determine the daily dose level of mannitol or fructans that induces symptom recurrence in IBS.	18 months

Collaborators and Investigators

• Sponsor: Universitaire Ziekenhuizen KU Leuven
• Collaborators: AZ Sint-Lucas Brugge

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2023
• Primary Completion (Actual): August 25, 2025
• Study Completion (Actual): August 25, 2025

Study Registration Dates

• First Submitted: March 15, 2023
• First Submitted That Met QC Criteria: April 7, 2023
• First Posted (Actual): April 11, 2023

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Mannitol; Fructans; FODMAP reintroduction
• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Colonic Diseases, Functional; Irritable Bowel Syndrome
• Other Study ID Numbers: S67424

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No