Irritable Bowel SyndromePhase 3NCT05120752
Efficacy of a Low FODMAP Diet in the Absence of Lactose Malabsorption in Moderate to Severe ROME IV IBS.
A Phase 3 study testing FODMAP diet in people with Irritable Bowel Syndrome, run by Universitair Ziekenhuis Brussel at 1 site in Belgium.
Trial summary
Irritable bowel syndrome (IBS) is a frequently encountered disorder. According to the Rome IV criteria, it is characterized by abdominal pain associated with a change in stool frequency or con-sistency, or with symptomatic improvement by defecation (Mearin 2016). Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Irritable Bowel Syndrome
- What is being tested?
- FODMAP diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteBelgium
- Study dates
- 2 Nov 2021to Jan 2028
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- - Patients aged 18 - 75 years;
- Fulfilling the ROME IV criteria for IBS;
- Moderate symptom severity as defined by a IBS-SSS > 175;
- Consumption of lactose containing products.
Who cannot join
- - Clinical suspicion of an organic disorder different from LI or IBS (patients can be included when this disorder had been excluded);
- Known lactose intolerance;
- Known inflammatory bowel disorder;
- Known major intestinal motility disorder;
- Alcohol (defined as more than 14 U per week) or other substance abuse;
- Active psychiatric disorder;
Show all 16Show fewer
- Known systemic or auto-immune disorder with implication for the GI system;
- Prior abdominal surgery (with the exception of appendectomy);
- Any prior diagnosis of cancer other than basocellular carcinoma;
- Current chemotherapy;
- History of gastro-enteritis in the past 8 weeks;
- Intake of antibiotics, pre- or probiotics during the past 8 weeks;
- Dietary supplements unless taken at a stable dose for more than 8 weeks;
- Treatment with neuromodulators (one neuromodulator taken at a stable dose for more than 12 weeks is allowed);
- Treatment with spasmolytic agents, opioids, loperamide, gelatin tannate or mucoprotectants during the past 8 weeks;
- LFD or low FODMAP diet in the past.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
UZ Brussel
Jette, Brussels Capital, 1090
Sébastien Kindt, MD
About this study
Irritable bowel syndrome (IBS) is a frequently encountered disorder. According to the Rome IV criteria, it is characterized by abdominal pain associated with a change in stool frequency or con-sistency, or with symptomatic improvement by defecation (Mearin 2016). Associated symptoms, such as bloating and flatulence, are frequently reported. The underlying pathophysiology remains obscure, although several pathways have been proposed. Low-grade immune activation, visceral hypersensitivity, alteration in gut microbiome have all been reported (Mearin 2016). As diet exerts an impact on all these pathophysiological mechanisms, the role of dietary intervention receives spe-cial attention, with special interest in the role played by so-called fermentable oligo-, di-, monosac-charides and polyols (FODMAPs). Multiple studies indicated the beneficial effects of the low FODMAP diet in at least part of the patients (Halmos 2014, Eswaran 2016, Staudacher 2017).
As a disaccharide, lactose is part of the FODMAPs. Lactose intolerance (LI) results from lactose malabsorption (LM) secondary to insufficient hydrolysis of the disaccharide lactose into galactose and glucose (Misselwitz 2019). The undigested lactose will eventually reach the colon, resulting in fermentation from colonic bacteria with production of different compounds such as short chain fat-ty acids, carbon dioxide, H2 and methane (Catanzaro 2021). These compounds have an osmotic effect and can stimulate colonic contractions. In patients suffering from LI, these pathophysiologi-cal mechanisms generate symptoms such as abdominal pain and cramps, flatulence, diarrhea, in-creased bowel sounds, among others, similar to the mechanisms by which FODMAPs induce symp-toms of IBS. As dairy products are highly present in our Western diet, LI will often be considered in patients presenting with such symptoms and they will be referred for further testing. When LM is diagnosed, a lactose-free diet (LFD) will be advocated to alleviate symptoms.
Read more
While the earlier-mentioned studies investigated symptomatic improvement by the low FODMAP diet, it remains uncertain whether this restrictive diet remains beneficial in patients without evidence of LM. In a recent study the low FODMAP diet and LFD provided comparable improvement in symptom severity (Krieger-Grübel 2020).
This study aims to:
- Assess the improvement in IBS symptoms and quality of life (QOL) by a low FODMAP di-et when lactose malabsorption has been previously excluded;
- Compare the improvement in IBS symptoms and QOL obtained by a low FODMAP diet to a lactose free diet (data from the PreVaIL study).
- Conditions
- Irritable Bowel Syndrome
- Being tested
- FODMAP diet
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FODMAP dietOther
all participants need to follow a low FODMAP diet, the information will be given by a trained dietitian
| Study group | Role | What they receive |
|---|---|---|
| FODMAP diet | Experimental | Not described Receives: Other: FODMAP diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
symptomatic improvement
To evaluate the symptomatic improvement by a low FODMAP diet in Rome IV IBS patients with-out documented lactose malabsorption.
Measured: 3 to 4 months
Evolution of Quality of life scale
Evolution of quality of life by the low FODMAP diet.
Measured: 3 to 4 months
Secondary outcomes (1)
reduction in Irritable bowel syndrome - symptom severity scale
Reduction of IBS-SSS at 4 weeks of diet vs. baseline depending on the reduction of FOD-MAP consumption;
Measured: baseline till week 4, baseline till week 16
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Nov 2021
- Study start2 Nov 2021
- Primary completionJan 2028 (estimated)
- Study completionJan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel SyndromeStudies of the same condition, open and under way.
- More trials run by Universitair Ziekenhuis BrusselThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitair Ziekenhuis Brussel
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Sébastien Kindt, MD, Principal investigator, Universitair Ziekenhuis Brussel
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05120752
- Sponsor's protocol ID
- AMaIFI
- Status last verified
- Dec 2025
- First submitted
- 13 Jul 2021
- Last updated
- 18 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of a Low FODMAP Diet in the Absence of Lactose Malabsorption in Moderate to Severe ROME IV IBS.
- ClinicalTrials.gov ID
- NCT05120752
- Acronym / sponsor ID
- AMaIFI
- Conditions
- Irritable Bowel Syndrome
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Universitair Ziekenhuis BrusselUniversity, hospital or other
- Study start
- 2 Nov 2021 (actual)
- Primary completion
- Jan 2028 (estimated)
- Study completion
- Jan 2028 (estimated)
- First posted
- 15 Nov 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Irritable bowel syndrome (IBS) is a frequently encountered disorder. According to the Rome IV criteria, it is characterized by abdominal pain associated with a change in stool frequency or con-sistency, or with symptomatic improvement by defecation (Mearin 2016). Associated symptoms, such as bloating and flatulence, are frequently reported. The underlying pathophysiology remains obscure, although several pathways have been proposed. Low-grade immune activation, visceral hypersensitivity, alteration in gut microbiome have all been reported (Mearin 2016). As diet exerts an impact on all these pathophysiological mechanisms, the role of dietary intervention receives spe-cial attention, with special interest in the role played by so-called fermentable oligo-, di-, monosac-charides and polyols (FODMAPs). Multiple studies indicated the beneficial effects of the low FODMAP diet in at least part of the patients (Halmos 2014, Eswaran 2016, Staudacher 2017).
As a disaccharide, lactose is part of the FODMAPs. Lactose intolerance (LI) results from lactose malabsorption (LM) secondary to insufficient hydrolysis of the disaccharide lactose into galactose and glucose (Misselwitz 2019). The undigested lactose will eventually reach the colon, resulting in fermentation from colonic bacteria with production of different compounds such as short chain fat-ty acids, carbon dioxide, H2 and methane (Catanzaro 2021). These compounds have an osmotic effect and can stimulate colonic contractions. In patients suffering from LI, these pathophysiologi-cal mechanisms generate symptoms such as abdominal pain and cramps, flatulence, diarrhea, in-creased bowel sounds, among others, similar to the mechanisms by which FODMAPs induce symp-toms of IBS. As dairy products are highly present in our Western diet, LI will often be considered in patients presenting with such symptoms and they will be referred for further testing. When LM is diagnosed, a lactose-free diet (LFD) will be advocated to alleviate symptoms.
While the earlier-mentioned studies investigated symptomatic improvement by the low FODMAP diet, it remains uncertain whether this restrictive diet remains beneficial in patients without evidence of LM. In a recent study the low FODMAP diet and LFD provided comparable improvement in symptom severity (Krieger-Grübel 2020).
This study aims to:
- Assess the improvement in IBS symptoms and quality of life (QOL) by a low FODMAP di-et when lactose malabsorption has been previously excluded;
- Compare the improvement in IBS symptoms and QOL obtained by a low FODMAP diet to a lactose free diet (data from the PreVaIL study).
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| FODMAP diet | Experimental | Other: FODMAP diet |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- - Patients aged 18 - 75 years;
- Fulfilling the ROME IV criteria for IBS;
- Moderate symptom severity as defined by a IBS-SSS > 175;
- Consumption of lactose containing products.
Key exclusion criteria (16 listed)
- - Clinical suspicion of an organic disorder different from LI or IBS (patients can be included when this disorder had been excluded);
- Known lactose intolerance;
- Known inflammatory bowel disorder;
- Known major intestinal motility disorder;
- Alcohol (defined as more than 14 U per week) or other substance abuse;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| FODMAP dietall participants need to follow a low FODMAP diet, the information will be given by a trained dietitian | Other | FODMAP diet |
Primary outcome
symptomatic improvement
Time frame: 3 to 4 months
To evaluate the symptomatic improvement by a low FODMAP diet in Rome IV IBS patients with-out documented lactose malabsorption.
Evolution of Quality of life scale
Time frame: 3 to 4 months
Evolution of quality of life by the low FODMAP diet.
1 secondary outcome
reduction in Irritable bowel syndrome - symptom severity scale
Time frame: baseline till week 4, baseline till week 16
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Sébastien Kindt, MD principal investigator
Universitair Ziekenhuis Brussel
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing FODMAP diet in people with Irritable Bowel Syndrome, run by Universitair Ziekenhuis Brussel at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sébastien Kindt, MD (+32 2 476 ext. 37 15, sebastien.kindt@uzbrussel.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
symptomatic improvement (time frame: 3 to 4 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Dec 2025.