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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
320
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.
Auburn Hospital
Auburn, New South Wales, Australia
Westmead Hospital
Westmead, New South Wales, Australia
Final total Boston Bowel Preparation Scale (BBPS) score on blinded external 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 video of the withdrawal phase.
Time frame: During colonoscopy withdrawal (single procedure)
Segmental Boston Bowel Preparation Scale scores on blinded external 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 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 and proximal
Proportion of participants with at least one histologically confirmed sessile serrated lesion in any segment, and separately proximal to the splenic flexure.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Polyp detection rate, adenomas per colonoscopy and serrated polyps per colonoscopy
Proportion of participants with at least one polyp of any histology; mean number of adenomas detected per colonoscopy; and mean number of sessile serrated lesions or hyperplastic polyps proximal to the splenic flexure detected per colonoscopy.
Time frame: From colonoscopy until histopathology results are available, up to 4 weeks
Operator-recorded BBPS compared with blinded external video review
Right colon BBPS recorded by the proceduralist at first inspection after caecal intubation and at the end of the examination, and total BBPS recorded by the proceduralist, compared with the corresponding scores from blinded external video review.
Time frame: During colonoscopy (single procedure)
Intra-procedural water volume and procedural efficiency measures
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; total procedure time; withdrawal time excluding cleansing manoeuvres and therapeutic interventions; and sedation dose and duration.
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
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