Systematic reviewindependent cross-checkabstract only checked I-INTC-10 standard review
Bowel inflammation after weight-loss surgery
Systematic review: Outcomes of bariatric surgery in patients with inflammatory bowel disease and de-novo IBD development after bariatric surgery.
Overview
Mian A et al.. Surgeon 2023 · PMID 35660070 · DOI 10.1016/j.surge.2022.04.008
Some studies report new inflammatory bowel disease after weight-loss surgery, but how often and whether surgery causes it is unknown.
Does the study support the specific claim? Partly · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Review bariatric surgery and IBD
- How was the study done?
Systematic review of 22 studies
- How many people, animals or samples were studied?
Patients with/without IBD
- What was actually found?
Safe in IBD; de novo IBD reported
- How large was the observed effect?
not reported
- What do the results mean in everyday life?
A possible rare link exists but is unproven.
- What are the study's limitations?
Weak study types; no rates
- What does it say about Elawady's specific claim?
Weak partial support
- Do the results apply to Germany and Europe?
High
- What can explicitly not be concluded from this study?
Causation
Scientific in-depth review
1. Full reference
- Authors
- Mian A et al.
- Journal
- Surgeon
- Year
- 2023
- Identifier
- PMID 35660070 DOI 10.1016/j.surge.2022.04.008
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
What are outcomes of bariatric surgery in IBD, and does de novo IBD develop after surgery?
3. Study design and population
- Study design
- Systematic review – Systematic review (PRISMA) of 22 studies
- Population
Patients with or without IBD undergoing bariatric surgery
- Country
International
- Period
Studies up to March 2020
- Sample size
22 studies
- Inclusion and exclusion criteria
PubMed/MEDLINE; bariatric procedures and IBD terms
4. Methods and endpoints
- Exposure / intervention
Bariatric surgery (incl. sleeve gastrectomy, RYGB)
- Comparator
not stated
- Endpoints
Safety, weight loss, IBD course, de novo IBD
- Statistical methods
Narrative synthesis
5. Actual results
- Results
Abstract: bariatric surgery was safe and effective in patients with IBD with significant weight loss at 6 and 12 months; multiple studies reported de novo IBD development following bariatric surgery in a selection of patients (no rates given in the abstract).
- Absolute risks
not reported
- Authors' conclusion
Bariatric surgery is safe in IBD; some evidence suggests it may precipitate de novo IBD.
6. Strengths
- Systematic search
7. Weaknesses
- Mostly case reports/series and observational data
- No incidence comparison in abstract
- Two databases only
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- high
- Rationale
Limited search, unclear quality appraisal; informal judgement.
9. Assessment of the statistical interpretation
No effect size; de novo cases cannot establish causation without a comparison group.
10. Relevance to the specific claim
Provides a weak signal that IBD (an immune-mediated disease) has been reported after bariatric surgery including sleeve gastrectomy; causation and frequency are not established.
11. Independent contrary findings
No comparative incidence data in the abstract.
12. Transferability to Germany and Europe
Applicable.
13. Overall methodological judgement
Weak, hypothesis-level support for one part of the claim.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | high |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | unknown |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Whether the de novo IBD rate is higher than expected.
15. Linked fact checks
- Sleeve gastrectomy causes autoimmune diseases and fibromyalgia. – Studies with mixed or unclear results