Narrative reviewindependent cross-checkfull text checked I-INTC-08 standard review
Food balls that block the gut are rare
Review of the diagnosis and management of gastrointestinal bezoars.
Overview
Iwamuro M et al.. World J Gastrointest Endosc 2015 · PMID 25901212 · DOI 10.4253/wjge.v7.i4.336
Bezoars cause 0.4-4.8% of intestinal blockages, mostly in people with stomach surgery or slow stomach emptying.
Does the study support the specific claim? No · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Review bezoars
- How was the study done?
Narrative review plus case series
- How many people, animals or samples were studied?
31 own cases; literature
- What was actually found?
Rare; linked to delayed emptying and gastric surgery
- How large was the observed effect?
0.4%-4.8% of intestinal obstruction cases
- What do the results mean in everyday life?
Healthy people rarely get blockages from food.
- What are the study's limitations?
Narrative; partly small series
- What does it say about Elawady's specific claim?
Limits the claim to rare risk groups
- Do the results apply to Germany and Europe?
Moderate
- What can explicitly not be concluded from this study?
Effect of chewing alone
Scientific in-depth review
1. Full reference
- Authors
- Iwamuro M et al.
- Journal
- World J Gastrointest Endosc
- Year
- 2015
- Identifier
- PMID 25901212 DOI 10.4253/wjge.v7.i4.336
- Verification
- verified – PubMed efetch 2026-10-25; full text read at https://pmc.ncbi.nlm.nih.gov/articles/PMC4400622/
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
Not stated in record
2. Research question
What are the prevalence, types, predisposing factors, diagnosis and treatment of gastrointestinal bezoars?
3. Study design and population
- Study design
- Narrative review – Narrative review with the authors' case series (31 Japanese patients)
- Population
Patients with bezoars
- Country
Japan (case series); international literature
- Period
not stated
- Sample size
31 cases in own series
- Inclusion and exclusion criteria
not applicable
4. Methods and endpoints
- Exposure / intervention
Bezoar formation
- Comparator
not applicable
- Endpoints
Prevalence, presentation, treatment
- Statistical methods
Descriptive
5. Actual results
- Results
Full text (PMC4400622, read 2026-10-25): bezoars are found in the stomach in less than 0.5% of people undergoing gastroscopy and in the small intestine in 0.4%-4.8% of cases presenting with intestinal obstruction; in one series of 1061 patients with acute small bowel obstruction bezoars were the 5th most common cause (0.8%). Bezoars are believed to form as a complication of delayed gastric emptying; predisposing factors include prior gastric surgery (partial gastrectomy, vagotomy, pyloroplasty), peptic ulcer disease, chronic gastritis, Crohn's disease, gastrointestinal cancer, dehydration and hypothyroidism; elderly people and diabetic patients with neuropathy have impaired gastric motility. Prevalence varies with food culture (e.g. persimmon).
- Absolute risks
Bezoars in 0.4%-4.8% of intestinal obstruction cases
- Authors' conclusion
Bezoars are relatively infrequent; Coca-Cola dissolution is a first choice for phytobezoars.
6. Strengths
- Full text read
- Summarises prevalence data
7. Weaknesses
- Narrative; based partly on own small case series
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
Prevalence ranges from cited studies; not pooled.
10. Relevance to the specific claim
Food-related obstruction (bezoar) exists but is infrequent and linked mainly to delayed gastric emptying and prior gastric surgery, not to normal chewing in healthy people.
11. Independent contrary findings
None.
12. Transferability to Germany and Europe
Prevalence may differ by food culture.
13. Overall methodological judgement
Good context for the rare kernel of truth in the chewing-obstruction claim.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | not assessable |
| Precision of results | low |
| Directness | indirect |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Role of poor chewing as an independent risk factor was not quantified.
15. Linked fact checks
- Food that is not chewed well is not fully digested in the stomach, and this incomplete digestion leads to intestinal obstruction. – Studies contradicting or limiting the claim