How PEG bowel preparation affects gut bacteria in people with or without an appendix
Official title: Impact of Polyethylene Glycol (PEG) Bowel Preparation on Intestinal Microbiota Composition and Diversity in Patients Undergoing Appendectomy
Run by Tongji Hospital · NCT07478029 · Data updated 2026-11-12
This observational study will test whether polyethylene glycol colonoscopy prep changes gut bacteria differently in adults who have had an appendectomy compared with those who have not.
Quick facts
| Study type | Observational |
|---|---|
| Ages | 18 Years to 75 Years |
| Sex | All |
| Enrollment | 10 (estimated) |
| Sponsor | Tongji Hospital Academic / other |
| Locations | 1 site (Wuhan, Hubei) |
| Status | Recruiting |
| Started | February 23, 2024 |
| Main results expected | February 23, 2027 |
| Study ends | March 18, 2027 |
| Registry record updated | March 17, 2026 |
| Trial ID | NCT07478029 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Adults 18–75 years old who are scheduled for colonoscopy, generally healthy, have not used antibiotics in the prior six months, and either have a history of appendectomy/right hemicolectomy or have an intact appendix.
✕Probably not a fit
People who recently took antibiotics, are pregnant or breastfeeding, have major organ disease or contraindications to colonoscopy, or have significant mental disorders are unlikely to benefit from participation.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This single-center observational study at Tongji Hospital will enroll adults aged 18–75 undergoing colonoscopy and group them by prior appendectomy (or right hemicolectomy) versus intact appendix. Participants will receive standard PEG bowel preparation and provide stool samples before and after the prep for microbiome analysis. The study will compare changes in microbial diversity, shifts in key taxa, and related metabolic markers between the groups while excluding recent antibiotic users and those with major comorbidities or colonoscopy contraindications. The aim is to determine whether the appendix influences microbiome disruption or recovery after PEG bowel cleansing.
Why it matters
Potential benefit: If successful, the findings could clarify whether appendectomy modifies PEG's effects on the gut microbiome and help inform safer colonoscopy preparation practices.
How similar studies have gone: Previous research has shown that PEG bowel preparation produces acute changes in gut microbial diversity and composition, but long-term effects and the specific protective or reservoir role of the appendix remain underexplored.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Aged 18-75 years. * Scheduled to undergo colonoscopy. * Generally healthy without major organ diseases. 1. For appendectomy group: history of appendectomy or right hemicolectomy (including appendectomy). 2. For control group: no history of appendectomy or right hemicolectomy. Exclusion Criteria: * Allergy or intolerance to PEG laxatives. * Pregnant or lactating women. * Mental disorders. * Use of antibiotics within 6 months prior to study enrollment. 1. Contraindications to colonoscopy (e.g., severe cardiopulmonary insufficiency). 2. For control group only: presence of organic diseases.
Where it's running
-
Department of Gastroenterology Tongji Hospital, Tongji Medical college, Huazhong University of Science and technology
Wuhan, Hubei, China Recruiting
Study contacts
- Study coordinator: ping h Xie
- Email: hpxie@tjh.tjmu.edu.cn
- Phone: 86+13437187007
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.