Irritable Bowel SyndromeIBS-DIETNCT07774923
Dietary Interventions for Irritable Bowel Syndrome
A study testing Low-FODMAP Diet and Gluten-Free and Lactose-Free Diet in people with Irritable Bowel Syndrome, run by Istanbul Gelisim University at 1 site in Turkey (Türkiye).
Trial summary
Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by recurrent abdominal pain and altered bowel habits. Dietary factors may trigger or worsen symptoms such as abdominal pain, bloating, gas, diarrhea, and constipation. Read more about this study
- Who is it for?
- Ages 18 to 64 years
- Conditions the study is for
- Irritable Bowel Syndrome
- What is being tested?
- Low-FODMAP Diet and Gluten-Free and Lactose-Free Diet
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 25 Feb 2025to 18 Jul 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 64 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Adults aged 19-64 years
- Diagnosed with irritable bowel syndrome
- Male or female
- Provided written informed consent to participate in the study
Who cannot join
- Pregnancy or lactation
- Diagnosis of cancer
- Presence of a gastrointestinal disease other than irritable bowel syndrome
- Diagnosis of diabetes mellitus
- Diagnosis of a psychiatric disorder
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effects of a Low-FODMAP Diet and Gluten-Free and Lactose-Free Dietary Interventions on Symptoms in Patients Diagnosed With Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by recurrent abdominal pain and altered bowel habits. Dietary factors may trigger or worsen symptoms such as abdominal pain, bloating, gas, diarrhea, and constipation. This study evaluated and compared the effects of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (low-FODMAP) diet and a combined gluten-free and lactose-free diet on symptom severity in adults diagnosed with IBS.
Adults aged 19-64 years with IBS followed one of the two dietary interventions for six weeks. IBS symptom severity was assessed at baseline and at the end of week 6 using the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). Dietary adherence was monitored by telephone during the intervention.
Read the detailed description
This interventional, parallel-group study was conducted at the Gastroenterology Outpatient Clinic of Mersin University Hospital between February 25 and July 18, 2025. The study included adults aged 19-64 years who had been diagnosed with irritable bowel syndrome, met the eligibility criteria, provided written informed consent, and agreed to follow the assigned dietary intervention.
Participants followed either a low-FODMAP diet or a combined gluten-free and lactose-free diet for six weeks. The low-FODMAP intervention restricted foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. The combined gluten-free and lactose-free intervention excluded foods containing gluten and lactose. Participants received detailed dietary instructions during the initial face-to-face visit.
At baseline, a researcher administered a data collection form covering sociodemographic characteristics, health information, dietary habits, and food preparation and cooking practices. Gastrointestinal symptom severity was measured using the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). The IBS-SSS produces a total score ranging from 0 to 500, with higher scores indicating greater symptom severity. It assesses abdominal pain severity, frequency of abdominal pain, abdominal bloating, satisfaction with bowel habits, and the interference of bowel symptoms with daily life.
Participants were contacted by telephone one week after starting the diet and subsequently at two-week intervals to monitor adherence. At the end of the six-week intervention, the IBS-SSS was administered again during a face-to-face visit. The primary analysis evaluated the change in IBS-SSS total score from baseline to week 6 and compared symptom changes between the two dietary intervention groups.
- Conditions
- Irritable Bowel Syndrome
- Being tested
- Low-FODMAP Diet, Gluten-Free and Lactose-Free Diet
- Keywords
- Low-FODMAP Diet, Gluten-Free Diet, Lactose-Free Diet, Dietary Intervention, Gastrointestinal Symptoms, IBS Symptom Severity Score
- 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.
Low-FODMAP DietBehavioural
Also called Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Diet
Participants followed a low-FODMAP diet for six weeks. Foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols were restricted. Participants received detailed dietary instructions during the initial face-to-face visit. Dietary adherence was monitored by telephone one week after starting the intervention and subsequently at two-week intervals.
Gluten-Free and Lactose-Free DietBehavioural
Also called Combined Gluten-Free and Lactose-Free Diet
Participants followed a combined gluten-free and lactose-free diet for six weeks. Foods containing gluten and lactose were excluded. Participants received detailed dietary instructions during the initial face-to-face visit. Dietary adherence was monitored by telephone one week after starting the intervention and subsequently at two-week intervals.
| Study group | Role | What they receive |
|---|---|---|
| Low-FODMAP Diet | Experimental | Participants followed a low-FODMAP diet for six weeks. The intervention restricted foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Dietary adherence was monitored by telephone during the intervention. Receives: Behavioral: Low-FODMAP Diet |
| Gluten-Free and Lactose-Free Diet | Active comparator | Participants followed a combined gluten-free and lactose-free diet for six weeks. The intervention excluded foods containing gluten and lactose. Dietary adherence was monitored by telephone during the intervention. Receives: Behavioral: Gluten-Free and Lactose-Free Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline in Irritable Bowel Syndrome Symptom Severity Score at Week 6
The Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) was used to assess overall IBS symptom severity. The instrument includes five domains: abdominal pain severity, frequency of abdominal pain, abdominal bloating severity, satisfaction with bowel habits, and interference of bowel symptoms with daily life. The total score ranges from 0 to 500, with higher scores indicating greater symptom severity. Change was calculated as the week 6 score minus the baseline score; a negative change indicates improvement.
Measured: Baseline and Week 6
Secondary outcomes (5)
Change From Baseline in Abdominal Pain Severity at Week 6
Abdominal pain severity was assessed using the corresponding IBS-SSS domain, scored from 0 to 100. Higher scores indicate greater abdominal pain severity. Change was calculated as the week 6 score minus the baseline score; a negative change indicates improvement.
Measured: Baseline and Week 6
Change From Baseline in Abdominal Pain Frequency at Week 6
Abdominal pain frequency was assessed using the corresponding IBS-SSS domain based on the number of days with abdominal pain during the previous 10 days. The domain score ranges from 0 to 100, with higher scores indicating more frequent abdominal pain. A negative change indicates improvement.
Measured: Baseline and Week 6
Change From Baseline in Abdominal Bloating Severity at Week 6
Abdominal bloating severity, including feelings of distension, fullness, and gas, was assessed using the corresponding IBS-SSS domain, scored from 0 to 100. Higher scores indicate greater symptom severity. A negative change indicates improvement.
Measured: Baseline and Week 6
Change From Baseline in Dissatisfaction With Bowel Habits at Week 6
Dissatisfaction with bowel habits was assessed using the corresponding IBS-SSS domain, scored from 0 to 100. Higher scores indicate greater dissatisfaction with bowel habits. A negative change indicates improvement.
Measured: Baseline and Week 6
Change From Baseline in Interference of Bowel Symptoms With Daily Life at Week 6
The interference of bowel symptoms with daily life was assessed using the corresponding IBS-SSS domain, scored from 0 to 100. Higher scores indicate greater interference with daily life. A negative change indicates improvement.
Measured: Baseline and Week 6
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2026
- Study start25 Feb 2025
- Primary completion18 Jul 2025
- Study completion18 Jul 2025
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.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants followed one of two dietary interventions for six weeks: a low-FODMAP diet or a combined gluten-free and lactose-free diet. Each participant remained in the same intervention arm throughout the study, with no crossover between arms.
- Masking
- None (open label)
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul Gelisim University
- Sponsor type
- University, hospital or other
- Collaborators
- Bahçeşehir University, Mersin University
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07774923
- Sponsor's protocol ID
- 78097791-020-3735
- Other IDs
- 78097791-020-3735
- Acronym
- IBS-DIET
- Status last verified
- Aug 2026
- First submitted
- 15 Aug 2026
- Last updated
- 20 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because the informed consent process did not include a specific provision for sharing participant-level data with external researchers.
Study at a glance
From the registry record, last updated by the sponsor on 20 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of a Low-FODMAP Diet and Gluten-Free and Lactose-Free Dietary Interventions on Symptoms in Patients Diagnosed With Irritable Bowel Syndrome
- ClinicalTrials.gov ID
- NCT07774923
- Acronym / sponsor ID
- IBS-DIET / 78097791-020-3735
- Conditions
- Irritable Bowel Syndrome
- Keywords
- Low-FODMAP Diet, Gluten-Free Diet, Lactose-Free Diet, Dietary Intervention, Gastrointestinal Symptoms, IBS Symptom Severity Score
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Istanbul Gelisim UniversityUniversity, hospital or other
- Collaborators
- Bahçeşehir University, Mersin University
- Study start
- 25 Feb 2025 (actual)
- Primary completion
- 18 Jul 2025 (actual)
- Study completion
- 18 Jul 2025 (actual)
- First posted
- 19 Aug 2026 (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 disorder of gut-brain interaction characterized by recurrent abdominal pain and altered bowel habits. Dietary factors may trigger or worsen symptoms such as abdominal pain, bloating, gas, diarrhea, and constipation. This study evaluated and compared the effects of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (low-FODMAP) diet and a combined gluten-free and lactose-free diet on symptom severity in adults diagnosed with IBS.
Adults aged 19-64 years with IBS followed one of the two dietary interventions for six weeks. IBS symptom severity was assessed at baseline and at the end of week 6 using the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). Dietary adherence was monitored by telephone during the intervention.
Detailed description
This interventional, parallel-group study was conducted at the Gastroenterology Outpatient Clinic of Mersin University Hospital between February 25 and July 18, 2025. The study included adults aged 19-64 years who had been diagnosed with irritable bowel syndrome, met the eligibility criteria, provided written informed consent, and agreed to follow the assigned dietary intervention.
Participants followed either a low-FODMAP diet or a combined gluten-free and lactose-free diet for six weeks. The low-FODMAP intervention restricted foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. The combined gluten-free and lactose-free intervention excluded foods containing gluten and lactose. Participants received detailed dietary instructions during the initial face-to-face visit.
At baseline, a researcher administered a data collection form covering sociodemographic characteristics, health information, dietary habits, and food preparation and cooking practices. Gastrointestinal symptom severity was measured using the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). The IBS-SSS produces a total score ranging from 0 to 500, with higher scores indicating greater symptom severity. It assesses abdominal pain severity, frequency of abdominal pain, abdominal bloating, satisfaction with bowel habits, and the interference of bowel symptoms with daily life.
Participants were contacted by telephone one week after starting the diet and subsequently at two-week intervals to monitor adherence. At the end of the six-week intervention, the IBS-SSS was administered again during a face-to-face visit. The primary analysis evaluated the change in IBS-SSS total score from baseline to week 6 and compared symptom changes between the two dietary intervention groups.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants followed one of two dietary interventions for six weeks: a low-FODMAP diet or a combined gluten-free and lactose-free diet. Each participant remained in the same intervention arm throughout the study, with no crossover between arms.
| Arm | Type | Receives |
|---|---|---|
| Low-FODMAP Diet | Experimental | Behavioral: Low-FODMAP DietParticipants followed a low-FODMAP diet for six weeks. The intervention restricted foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Dietary adherence was monitored by telephone during the intervention. |
| Gluten-Free and Lactose-Free Diet | Active comparator | Behavioral: Gluten-Free and Lactose-Free DietParticipants followed a combined gluten-free and lactose-free diet for six weeks. The intervention excluded foods containing gluten and lactose. Dietary adherence was monitored by telephone during the intervention. |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Adults aged 19-64 years
- Diagnosed with irritable bowel syndrome
- Male or female
- Provided written informed consent to participate in the study
Key exclusion criteria (5 listed)
- Pregnancy or lactation
- Diagnosis of cancer
- Presence of a gastrointestinal disease other than irritable bowel syndrome
- Diagnosis of diabetes mellitus
- Diagnosis of a psychiatric disorder
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 |
|---|---|---|
| Low-FODMAP DietAlso: Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols DietParticipants followed a low-FODMAP diet for six weeks. Foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols were restricted. Participants received detailed dietary instructions during the initial face-to-face visit. Dietary adherence was monitored by telephone one week after starting the intervention and subsequently at two-week intervals. | Behavioural | Low-FODMAP Diet |
| Gluten-Free and Lactose-Free DietAlso: Combined Gluten-Free and Lactose-Free DietParticipants followed a combined gluten-free and lactose-free diet for six weeks. Foods containing gluten and lactose were excluded. Participants received detailed dietary instructions during the initial face-to-face visit. Dietary adherence was monitored by telephone one week after starting the intervention and subsequently at two-week intervals. | Behavioural | Gluten-Free and Lactose-Free Diet |
Primary outcome
Change From Baseline in Irritable Bowel Syndrome Symptom Severity Score at Week 6
Time frame: Baseline and Week 6
The Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) was used to assess overall IBS symptom severity. The instrument includes five domains: abdominal pain severity, frequency of abdominal pain, abdominal bloating severity, satisfaction with bowel habits, and interference of bowel symptoms with daily life. The total score ranges from 0 to 500, with higher scores indicating greater symptom severity. Change was calculated as the week 6 score minus the baseline score; a negative change indicates improvement.
5 secondary outcomes
Change From Baseline in Abdominal Pain Severity at Week 6
Time frame: Baseline and Week 6
Change From Baseline in Abdominal Pain Frequency at Week 6
Time frame: Baseline and Week 6
Change From Baseline in Abdominal Bloating Severity at Week 6
Time frame: Baseline and Week 6
Change From Baseline in Dissatisfaction With Bowel Habits at Week 6
Time frame: Baseline and Week 6
Change From Baseline in Interference of Bowel Symptoms With Daily Life at Week 6
Time frame: Baseline and Week 6
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Aug 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared because the informed consent process did not include a specific provision for sharing participant-level data with external researchers.
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NEUROMODULATION WITH TRANSCUTANEOUS AURICULAR VAGUS NERVE STIMULATION IN ADULTS WITH IRRITABLE BOWEL SYNDROME: A RANDOMIZED, SINGLE-BLIND, SHAM-CONTROLLED CROSSOVER STUDY
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low-FODMAP Diet and Gluten-Free and Lactose-Free Diet in people with Irritable Bowel Syndrome, run by Istanbul Gelisim University at 1 site in Turkey (Türkiye).
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 5 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: finished, as of the sponsor's last update on 20 Aug 2026. 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 Turkey (Türkiye). 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.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change From Baseline in Irritable Bowel Syndrome Symptom Severity Score at Week 6 (time frame: Baseline and Week 6). 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 20 Aug 2026.