Right Colon Enema to Improve Bowel Preparation Quality During Colonoscopy
RIGHT-CLEAN
RIGHT-CLEAN Trial: A Multi-centre Randomised Controlled Trial of Intra-procedural Right Colon Enema Versus no Enema to Improve Total Colonic Bowel Preparation at Colonoscopy.
1 other identifier
interventional
320
1 country
2
Brief Summary
Colonoscopy is a test that lets doctors look inside the large bowel to find and remove growths called polyps, which can develop into bowel cancer. Before the test, people take a bowel preparation to empty the bowel. Even so, the right side of the bowel is often not clean enough, and polyps there can be missed. This study is testing whether giving an enema (a small amount of fluid passed into the bowel) during the colonoscopy makes the right side of the bowel cleaner. Participants having a routine colonoscopy at Westmead Hospital or Auburn Hospital will be assigned by chance to either receive the enema during the procedure or to have their colonoscopy in the usual way. Neither group takes any extra preparation at home. The researchers will compare how clean the right side of the bowel is in each group, using a standard scoring system, and will also look at how many polyps are found. The aim is to find out whether this simple step improves the quality of colonoscopy.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Nov 2026
Typical duration for not_applicable
2 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
September 4, 2026
CompletedFirst Posted
Study publicly available on registry
September 10, 2026
CompletedStudy Start
First participant enrolled
November 1, 2026
ExpectedPrimary Completion
Last participant's last visit for primary outcome
November 1, 2028
Study Completion
Last participant's last visit for all outcomes
November 1, 2028
September 24, 2026
September 1, 2026
2 years
September 4, 2026
September 20, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Final total Boston Bowel Preparation Scale (BBPS) score on blinded external image and video review
Sum of the segmental BBPS scores for the right, transverse and left colon (range 0-9, higher scores indicate better cleansing), determined by external expert reviewers masked to allocation from de-identified images and video of the withdrawal phase.
During colonoscopy withdrawal (single procedure)
Secondary Outcomes (16)
Segmental Boston Bowel Preparation Scale scores on blinded external image and video review
During colonoscopy withdrawal (single procedure)
Proportion of participants achieving adequate bowel preparation
During colonoscopy withdrawal (single procedure)
Adenoma detection rate
From colonoscopy until histopathology results are available, up to 4 weeks
Proximal adenoma detection rate
From colonoscopy until histopathology results are available, up to 4 weeks
Sessile serrated lesion detection rate, overall
From colonoscopy until histopathology results are available, up to 4 weeks
- +11 more secondary outcomes
Study Arms (2)
Intra-procedural right colon Fleet enema
EXPERIMENTALImmediately after confirmed caecal intubation and randomisation, with the colonoscope tip in the right colon, a Fleet sodium phosphate enema is instilled into the right colon through the colonoscope working channel. The right colon is then refilled to the hepatic flexure using the foot-pump water jet. The fluid is not suctioned; the right lower quadrant is agitated by manual percussion. The lumen is re-insufflated with CO2 and the scope returned to the caecum before withdrawal begins, allowing the instilled solution and mobilised faecal residue to be carried distally through the transverse and left colon.
Water control
PLACEBO COMPARATORColonoscopy lets doctors look inside the large bowel to find and remove growths called polyps. Before the test, people take a bowel preparation to empty the bowel, but the right side of the bowel is often still not clean enough, and polyps there can be missed. This study is testing whether a small enema given through the colonoscope into the right side of the bowel, during the procedure, makes the whole bowel cleaner. Once the camera reaches the far end of the bowel, participants are assigned by chance to receive either the enema or the same volume of water. Everything else about the procedure is the same in both groups, and no extra preparation is taken at home. The recordings of each procedure are reviewed by independent experts who do not know which group the participant was in, and who score how clean each part of the bowel was. The researchers will also compare how many polyps were found in each group.
Interventions
A single Fleet sodium phosphate enema (monobasic sodium phosphate monohydrate 19 g and dibasic sodium phosphate heptahydrate 7 g in 118 mL of saline) is administered once, intra-procedurally, into the right colon through the colonoscope working channel after confirmed caecal intubation. The enema nozzle is aligned with the working channel for delivery. The volume instilled is recorded and is not counted towards intra-procedural water-jet lavage. No further doses are given.
Immediately after confirmed caecal intubation and randomisation, with the colonoscope tip in the right colon, 100 mL of water is instilled into the right colon through the colonoscope working channel using a syringe. All subsequent steps are identical to the intervention arm: the right colon is refilled to the hepatic flexure using the foot-pump water jet, the fluid is not suctioned, the right lower quadrant is agitated by manual percussion, and the lumen is re-insufflated with CO2 before the scope is returned to the caecum for withdrawal.
Eligibility Criteria
You may qualify if:
- Age 18 to 85 years
- Undergoing elective full colonoscopy for any indication
- Successful caecal intubation achieved during the procedure, confirmed prior to randomisation
- Able to provide written informed consent
You may not qualify if:
- Emergency colonoscopy
- Known inflammatory bowel disease with active colitis in the examined segment
- Familial polyposis syndromes
- Prior major right hemicolectomy or altered anatomy preventing standard right colon assessment
- Known obstructing colorectal malignancy precluding safe progression or adequate examination
- Pregnancy
- Renal failure (eGFR less than 30 mL/min)
- Previous sodium phosphate enema within the preceding 24 hours
- Contraindication to sodium phosphate administration as determined by the treating endoscopist
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (2)
Auburn Hospital
Auburn, New South Wales, 2144, Australia
Westmead Hospital
Westmead, New South Wales, 2145, Australia
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Study Officials
- STUDY DIRECTOR
Michael J Bourke, MBBS,FRACP
Westmead Hospita, Endoscopy Unit
- PRINCIPAL INVESTIGATOR
Nicholas G Burgess, MBChB, PhD, FRACP
Westmead Hospita, Endoscopy Unit
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- SINGLE
- Who Masked
- OUTCOMES ASSESSOR
- Masking Details
- Endoscopists performing the procedure cannot be masked. The withdrawal phase of every colonoscopy is video-recorded, de-identified and edited to remove any indication of allocation before review. Segmental and total BBPS are scored by external expert reviewers who are masked to allocation and are not involved in performing the study procedures. Statistical analysis is performed masked to allocation.
- Purpose
- DIAGNOSTIC
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Professor and Staff Specialist Gastroenterologist
Study Record Dates
First Submitted
September 4, 2026
First Posted
September 10, 2026
Study Start (Estimated)
November 1, 2026
Primary Completion (Estimated)
November 1, 2028
Study Completion (Estimated)
November 1, 2028
Last Updated
September 24, 2026
Record last verified: 2026-09
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP
- Time Frame
- Beginning 12 months after publication of the primary results and ending 5 years thereafter.
- Access Criteria
- De-identified individual participant data may be made available to investigators whose proposed use of the data has been approved by the Coordinating Principal Investigator, for analyses aimed at achieving the aims of an approved proposal. Requests should be directed to the Coordinating Principal Investigator. Data sharing is subject to WSLHD Human Research Ethics Committee approval and a data sharing agreement.
De-identified individual participant data underlying the published results will be available, including baseline demographic and clinical characteristics, colonoscopy indication, treatment allocation, operator-recorded and blinded video-review BBPS scores for each colonic segment, lesion detection and histopathology outcomes, procedural metrics (procedure and withdrawal times, sedation, intra-procedural water volume) and adverse events. Procedure videos will not be shared, as they are deleted once blinded review is complete. The linkage file containing identifiers will not be shared.