Narrative reviewindependent cross-checkabstract checked I-BAR-148 standard review
Review: how the gut works after sleeve or bypass
Adaptations in gastrointestinal physiology after sleeve gastrectomy and Roux-en-Y gastric bypass.
Overview
Steenackers et al.. Lancet Gastroenterol Hepatol 2021 · PMID 33581761 · DOI 10.1016/S2468-1253(20)30302-2
After sleeve, food leaves the stomach faster and bile acids rise; many other effects are still 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?
GI physiology after surgery
- How was the study done?
Narrative review
- How many people, animals or samples were studied?
not applicable
- What was actually found?
Faster emptying; unknowns
- How large was the observed effect?
not applicable
- What do the results mean in everyday life?
The stomach changes but keeps working
- What are the study's limitations?
Not systematic
- What does it say about Elawady's specific claim?
Premise partly correct
- Do the results apply to Germany and Europe?
Applicable
- What can explicitly not be concluded from this study?
Harm or benefit
Scientific in-depth review
1. Full reference
- Authors
- Steenackers et al.
- Journal
- Lancet Gastroenterol Hepatol
- Year
- 2021
- Identifier
- PMID 33581761 DOI 10.1016/S2468-1253(20)30302-2
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref API
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
How does gastrointestinal physiology adapt after sleeve gastrectomy and RYGB?
3. Study design and population
- Study design
- Narrative review – Narrative review
- Population
Preclinical and clinical studies
- Country
not applicable
- Period
2021
- Sample size
not applicable
- Inclusion and exclusion criteria
not stated
4. Methods and endpoints
- Exposure / intervention
SG and RYGB
- Comparator
not applicable
- Endpoints
Gastric emptying, transit, acidity, secretions, bile acids
- Statistical methods
not applicable
5. Actual results
- Results
SG accelerates liquid and solid gastric emptying and small-intestinal transit and increases serum bile acids; its effects on GI acidity, gastric and pancreatic secretions, surface area and colonic transit remain largely unknown. RYGB diminishes gastric acid secretion and accelerates liquid gastric emptying.
- Absolute risks
not applicable
- Authors' conclusion
Understanding GI physiology after surgery is crucial to prevent nutritional deficiencies and optimise drug therapy; knowledge gaps remain.
6. Strengths
- Authoritative overview
7. Weaknesses
- Narrative, not systematic
8. Risk of bias
- Orienting tool
- none applicable
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- not assessable
- Rationale
Narrative review.
9. Assessment of the statistical interpretation
not applicable
10. Relevance to the specific claim
Confirms that sleeve alters stomach physiology (emptying, transit) and that some functional consequences are still unknown - partial support for the premise of C-BAR-10, not for "functions lost".
11. Independent contrary findings
12. Transferability to Germany and Europe
International.
13. Overall methodological judgement
Supports altered (not lost) physiology.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | not assessable |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | unknown |
| Consistency with the overall evidence | unknown |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Acid secretion after SG.