Case-control studyindependent cross-checkabstract checked I-ORG-133 standard review
Fat in stools after gallbladder removal
Diet and faecal lipids following cholecystectomy in men.
Overview
Brydon WG et al.. Digestion 1982 · PMID 7166207 · DOI 10.1159/000198840
Men without a gallbladder lost somewhat more fat in their stools than men with one, though they ate the same diet.
Does the study support the specific claim? Partly · Methodological quality: very low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Compare stool fat after cholecystectomy
- How was the study done?
Small comparative study
- How many people, animals or samples were studied?
Men; number not given
- What was actually found?
More fat and heavier stools after surgery
- How large was the observed effect?
Not reported
- What do the results mean in everyday life?
Fat digestion may be slightly less efficient without a gallbladder
- What are the study's limitations?
Very small, old
- What does it say about Elawady's specific claim?
Supports the premise, not the advice
- Do the results apply to Germany and Europe?
Uncertain
- What can explicitly not be concluded from this study?
Cannot tell whether eating more fat compensates
Scientific in-depth review
1. Full reference
- Authors
- Brydon WG et al.
- Journal
- Digestion
- Year
- 1982
- Identifier
- PMID 7166207 DOI 10.1159/000198840
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Non-commercial support (PubMed).
2. Research question
Do faecal fat and bile acid excretion differ after cholecystectomy?
3. Study design and population
- Study design
- Case-control study – Small comparative (case-control) study of faecal lipids and diet
- Population
Men after cholecystectomy and age-matched controls
- Country
Not stated in abstract
- Period
Not stated
- Sample size
Not stated in abstract
- Inclusion and exclusion criteria
Male subjects
4. Methods and endpoints
- Exposure / intervention
Prior cholecystectomy
- Comparator
Age-matched controls
- Endpoints
Faecal fat, bile acids, sterols, stool weight; diet
- Statistical methods
Group comparisons
5. Actual results
- Results
Daily faecal fat excretion and concentration were significantly higher after cholecystectomy; bile acid and neutral sterol excretion not different; diets did not differ; stool weight higher after cholecystectomy.
- Absolute risks
Not reported (no numbers in abstract)
- Authors' conclusion
Faecal fat and stool weight higher after cholecystectomy despite similar diets.
6. Strengths
- Direct measurement of faecal fat
7. Weaknesses
- Very small, old, men only
- No numbers in abstract
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- high
- Rationale
Small observational comparison.
9. Assessment of the statistical interpretation
No effect sizes in abstract.
10. Relevance to the specific claim
Only direct evidence found that fat absorption is somewhat reduced after cholecystectomy (premise of the claim).
11. Independent contrary findings
n/a
12. Transferability to Germany and Europe
Unknown setting.
13. Overall methodological judgement
Supports the premise that fat absorption may be slightly reduced, but provides no support for eating more fat.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | very low |
| Risk of bias | high |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | unknown |
| Consistency with the overall evidence | unknown |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Magnitude of malabsorption.
15. Linked fact checks
- After gallbladder removal fat absorption falls, so patients should eat more fat (e.g., 200 g instead of 100 g) such as butter and ghee. – Studies with mixed or unclear results