An interventional study of Simethicone with PEG and PEG in Quality of Bowel Preparation, sponsored by Dalin Tzu Chi General Hospital. Not yet recruiting. Open to participants aged 20 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-29.
Sponsored by Dalin Tzu Chi General Hospital · Not applicable, Interventional, and Health services research
Background: Colonoscopy reduces colorectal cancer mortality by enabling early detection and removal of adenomas. Its effectiveness, however, depends heavily on bowel preparation quality and mucosal visibility. Simethicone, an anti-foaming agent, decreases intraluminal bubbles and improves visualization; studies in conventional air-insufflation colonoscopy generally show benefits for cleanliness and patient comfort, but evidence in water-exchange (WE) colonoscopy remains limited.Objective: To evaluate whether adding oral simethicone to a split-dose polyethylene glycol (PEG) regimen further improves bowel cleanliness and procedural performance in WE colonoscopy.Methods: Adults undergoing outpatient colonoscopy will be randomly assigned (1:1) to a simethicone group or a control group, with a planned enrollment of 180 participants. All procedures will use the WE insertion technique, and endoscopists will be blinded to group allocation. The primary endpoint is the Boston Bowel Preparation Scale (BBPS); adequate preparation is defined as a total score ≥6 with all segment scores ≥2. Secondary endpoints include bubble score and CEBuS, adenoma detection rate (ADR), polyp detection rate (PDR), cecal intubation rate and time, withdrawal time, volume of water used and flushing/irrigation metrics, and patient-reported tolerability and satisfaction.Expected Results: Compared with PEG alone, adding simethicone is expected to (1) increase the proportion of adequate BBPS preparations, (2) reduce bubble coverage, (3) maintain or potentially improve ADR/PDR, and (4) enhance patient tolerability and satisfaction.Conclusion: If effective, this intervention would provide a simple, low-cost strategy to optimize the quality of WE colonoscopy.
Exclusion Criteria:
follow a bowel preparation protocol consisting of 10 mg of bisacodyl and 2 liters of PEG solution.
Drug: PEG
Participants received a total of 30 mL of simethicone, with 15 mL added to each 1-liter dose of polyethylene glycol (PEG) solution in the split-dose regimen.
Drug: Simethicone with PEG
All participants followed a standardized bowel preparation protocol consisting of 10 mg of bisacodyl and 2 liters of PEG solution administered in a split-dose regimen. Participants in the simethicone group additionally received 30 mL of simethicone (600 mg), with 15 mL added to each 1-liter dose of PEG solution.
All participants followed a standardized bowel preparation protocol consisting of 10 mg of bisacodyl and 2 liters of PEG solution administered in a split-dose regimen.
Boston bowel preparation scale (BBPS)
Bowel preparation quality assessed using the Boston Bowel Preparation Scale (BBPS). Adequate preparation is defined as a total score ≥6 with all segment scores ≥2.
Time frame: At the time of colonoscopy.
Bubble score assessed using a 4-point bubble scale
Bubble score assessed during colonoscopy using a 4-point scale (0-3) for each colon segment, where higher scores indicate more bubbles.
Time frame: During the colonoscopy procedure.
Colon Endoscopic Bubble Scale(CEBuS)
Bowel cleanliness assessed using the Colon Endoscopic Bubble Scale (CEBuS), categorized based on the percentage of mucosal surface obscured by bubbles (e.g., \<5%, 5-50%, \>50%).Higher scores indicate poorer visibility due to bubbles.
Time frame: During the colonoscopy procedure.
Adenoma detection rate (ADR)
Time frame: one week
Polyp detection rate (PDR)
Time frame: one week
Cecal intubation rate
Proportion of procedures in which the cecum is successfully reached.
Time frame: At the time of colonoscopy.
Cecal intubation time
Time from insertion to successful cecal intubation, measured in minutes.
Time frame: During the colonoscopy procedure.
Withdrawal time
Time from cecal intubation to scope withdrawal, measured in minutes.
Time frame: During the colonoscopy procedure.
Volume of water infused
Total volume of water infused during colonoscopy, measured in milliliters.
Time frame: During the procedure.
Volume of fluid aspirated
Total volume of fluid aspirated during colonoscopy, measured in milliliters.
Time frame: During the procedure
Patient-reported pain score
Pain assessed using a visual analog scale (VAS) ranging from 0 (no pain) to 10 (worst pain imaginable).
Time frame: Immediately after the procedure.
Patient satisfaction score
Patient satisfaction assessed using a numeric rating scale from 0 to 10, where higher scores indicate greater satisfaction.
Time frame: Immediately after the procedure.
No study locations are listed for this record.
This study is not yet recruiting, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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Dalin Tzu Chi General Hospital