Randomised controlled trialindependent cross-checkabstract checked★ key study I-GUT-103 in-depth review
Three diets for IBS worked about equally
Efficacy and Acceptability of Dietary Therapies in Non-Constipated Irritable Bowel Syndrome: A Randomized Trial of Traditional Dietary Advice, the Low FODMAP Diet, and the Gluten-Free Diet.
Overview
Rej A et al.. Clin Gastroenterol Hepatol 2022 · PMID 35240330 · DOI 10.1016/j.cgh.2022.02.045
In 99 IBS patients, about half improved meaningfully after 4 weeks on a gluten-free, low-FODMAP or standard advice diet.
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Compare three IBS diets.
- How was the study done?
Randomised trial, 4 weeks.
- How many people, animals or samples were studied?
99 adults with IBS without constipation.
- What was actually found?
Responders 42%, 55%, 58%; no significant difference.
- How large was the observed effect?
Gluten-free 58% (19/33).
- What do the results mean in everyday life?
Removing wheat can help some people, but not most of them dramatically.
- What are the study's limitations?
Small, unblinded, no untreated group.
- What does it say about Elawady's specific claim?
Contradicts the 85% figure; supports partial benefit.
- Do the results apply to Germany and Europe?
UK data; applicable to Europe.
- What can explicitly not be concluded from this study?
Cannot show a cure or effects beyond 4 weeks.
Scientific in-depth review
1. Full reference
- Authors
- Rej A et al.
- Journal
- Clin Gastroenterol Hepatol
- Year
- 2022
- Identifier
- PMID 35240330 DOI 10.1016/j.cgh.2022.02.045
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Not stated in abstract (non-US government research support listed in PubMed)
2. Research question
How do traditional dietary advice, low FODMAP and gluten-free diets compare in non-constipated IBS?
3. Study design and population
- Study design
- Randomised controlled trial – Randomised controlled trial, 3 parallel diet arms, 4 weeks, dietitian-led
- Population
Adults with Rome IV non-constipated IBS, UK tertiary centre
- Country
UK
- Period
Published 2022 (NCT04072991)
- Sample size
99 (33 per arm)
- Inclusion and exclusion criteria
Rome IV IBS-D/IBS-M; coeliac disease excluded
4. Methods and endpoints
- Exposure / intervention
Gluten-free diet (removing wheat, barley, rye) or low FODMAP diet
- Comparator
Traditional dietary advice (BDA/NICE)
- Endpoints
Responder: >=50-point fall in IBS-SSS at 4 weeks; acceptability, nutrition, dysbiosis index
- Statistical methods
Comparison of responder proportions (chi-square)
5. Actual results
- Results
Responders: TDA 42% (14/33), LFD 55% (18/33), GFD 58% (19/33); P=0.43. TDA cheaper and easier. Dysbiosis index similar across diets.
- Absolute risks
Responder proportions 42-58% at 4 weeks
- Authors' conclusion
All three diets are effective; traditional advice is the most patient-friendly first choice.
6. Strengths
- Randomised head-to-head
- Validated symptom score
- Gluten-free arm is the closest tested analogue to stopping bread
7. Weaknesses
- Small, underpowered for differences
- No habitual-diet control arm
- Open label
- Single centre
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Unblinded diets; subjective outcome; no untreated control.
9. Assessment of the statistical interpretation
Wilson 95% CI for the gluten-free responder rate 41%-73% excludes 85% (stats/C-GUT-01_02_diet_trials.py).
10. Relevance to the specific claim
Closest RCT test of 'stopping wheat/bread' in IBS: improvement in about half, not 85%, after 4 weeks.
11. Independent contrary findings
Without a no-change control, part of the response may be placebo or regression to the mean.
12. Transferability to Germany and Europe
UK population; transferable in principle.
13. Overall methodological judgement
Supports modest benefit; contradicts the 85% in 10 days figure.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | direct |
| Reproducibility | not replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Effect of bread removal in Egyptian diets; long-term adherence.
15. Linked fact checks
- Reflux (heartburn) and irritable bowel syndrome are largely driven by eating habits; removing white/baladi bread, baked goods and soft drinks can improve symptoms. – Studies supporting the claim
- Stopping bread and baked goods for five days will improve 85% of reflux and IBS symptoms within at most ten days; both diseases can be eliminated completely. – Studies contradicting or limiting the claim