An interventional study of Sodium phosphate enema and Water instillation in Colonic Polyps, Colorectal Neoplasms and Colonoscopy, sponsored by Westmead Hospital. Not yet recruiting at 2 sites in Australia. Open to participants aged 18 Years to 85 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-24.
Sponsored by Westmead Hospital · Not applicable, Interventional, and Diagnostic
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.
Adequate mucosal visualisation in the right colon remains a limitation of colonoscopy despite standard oral bowel preparation, and residual debris in the caecum and ascending colon is associated with reduced adenoma detection and shortened surveillance intervals.
RIGHT-CLEAN is an investigator-initiated, multi-centre, randomised controlled trial conducted at Westmead Hospital and Auburn Hospital within Western Sydney Local Health District. Adults undergoing colonoscopy for [indication] will be randomised [1:1] to intraprocedural right colon enema or to standard colonoscopy without enema. Randomisation will be [method, stratified by site].
The primary outcome is [right-sided Boston Bowel Preparation Scale segment score]. Secondary outcomes include [adenoma detection rate, caecal intubation and withdrawal times, need for additional washing, and participant-reported tolerability]. Assessment of cleanliness will be performed [by blinded assessors / from recorded still images]. A sample size of [n] participants provides [x]% power to detect [effect size] at a two-sided alpha of 0.05.
All participants will provide written informed consent. No investigational drug or device is used; the enema comprises [water/saline] administered through the colonoscope during the procedure.
377 studies on the registry are indexed under Colonic Polyps; 57 are open to participants now.
This study's planned enrollment of 320 is above the median of 274 across 250 interventional studies indexed under Colonic Polyps.
Browse Colonic Polyps studies →Westmead Hospital is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immediately 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.
Drug: Sodium phosphate enema
Colonoscopy 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.
Other: Water instillation
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.
Also known as: Fleet enema, Monobasic sodium phosphate monohydrate / dibasic sodium phosphate heptahydrate
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.
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.
Time frame: During colonoscopy withdrawal (single procedure)
Segmental Boston Bowel Preparation Scale scores on blinded external image and video review
BBPS score for each colonic segment (right, transverse and left colon), each scored 0-3, determined by external expert reviewers masked to allocation from de-identified images and video of the withdrawal phase.
Time frame: During colonoscopy withdrawal (single procedure)
Proportion of participants achieving adequate bowel preparation
Proportion of participants with a total BBPS of 6 or more with each segmental score of 2 or more, on blinded external video review.
Time frame: During colonoscopy withdrawal (single procedure)
Adenoma detection rate
Proportion of participants with at least one histologically confirmed conventional adenoma in any colonic segment.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Proximal adenoma detection rate
Proportion of participants with at least one histologically confirmed conventional adenoma proximal to the splenic flexure.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Sessile serrated lesion detection rate, overall
Proportion of participants with at least one histologically confirmed sessile serrated lesion in any segment
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Sessile serrated lesion detection rate, proximal
Proportion of participants with at least one histologically confirmed sessile serrated lesion proximal to the splenic flexure.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Polyp detection rate
Proportion of participants with at least one polyp of any histology detected per colonoscopy.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Operator-recorded total BBPS compared with blinded external video review
Total BBPS recorded by the proceduralist at the end of the examination, compared with the corresponding scores from blinded external video review.
Time frame: During colonoscopy (single procedure)
Operator-recorded Right Colon BBPS at first inspection compared with blinded external video review
Right colon BBPS recorded by the proceduralist at first inspection after caecal intubation compared with the corresponding scores from blinded external video review.
Time frame: During colonoscopy (single procedure)
Intra-procedural water volume
Total volume of water used during the examination, calculated as the filled water-jet bottle volume minus the residual volume, recorded separately from the volume of instilled study agent
Time frame: During colonoscopy (single procedure)
Adenomas per colonoscopy
Proportion of participants with at least adenomatous polyp; mean number of adenomas per colonoscopy.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Serrated polyps per colonoscopy
Proportion of participants with at least one serrated polyp; mean number of sessile serrated lesions per colonoscopy.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Total Procedure Time
Total time from endoscope insertion to endoscope withdrawal per procedure.
Time frame: During colonoscopy (single procedure)
Withdrawal Time
Total withdrawal time from caecum to endoscope removal.
Time frame: During colonoscopy (single procedure)
Need for early repeat colonoscopy due to inadequate preparation
Proportion of participants for whom an early repeat colonoscopy is booked or performed because of inadequate bowel preparation, ascertained by structured medical record review.
Time frame: 7 days after colonoscopy
Immediate and delayed adverse events
Immediate adverse events recorded in the recovery area, and delayed adverse events within 7 days ascertained by structured medical record review, including emergency department presentations, unplanned admissions, abdominal pain requiring medical evaluation, bleeding and perforation.
Time frame: From colonoscopy to 7 days after the procedure
Plan to share: Yes — 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.
Supporting information: Study protocol, Statistical analysis plan
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.
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This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Sodium phosphate
Westmead Hospital