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Randomized Controlled Trial
. 2021 May;70(5):845-852.
doi: 10.1136/gutjnl-2020-321918. Epub 2020 Sep 7.

WASh multicentre randomised controlled trial: water-assisted sigmoidoscopy in English NHS bowel scope screening

Matthew D Rutter  1   2 , Rachel Evans  3 , Zoe Hoare  3 , Christian Von Wagner  4 , Jill Deane  5 , Shiran Esmaily  5 , Tony Larkin  6 , Rhiannon Edwards  7 , Seow Tien Yeo  7 , Llinos Haf Spencer  7 , Emily Holmes  7 , Brian P Saunders  8 , Colin J Rees  2   9 , Zacharias P Tsiamoulos  8 , Iosif Beintaris  5 ; WASh trial team
Collaborators, Affiliations
Randomized Controlled Trial

WASh multicentre randomised controlled trial: water-assisted sigmoidoscopy in English NHS bowel scope screening

Matthew D Rutter et al. Gut. 2021 May.

Abstract

Objectives: The English Bowel Cancer Screening Programme invites 55 year olds for a sigmoidoscopy (Bowel Scope Screening (BSS)), aiming to resect premalignant polyps, thus reducing cancer incidence. A national patient survey indicated higher procedural pain than anticipated, potentially impacting on screening compliance and effectiveness. We aimed to assess whether water-assisted sigmoidoscopy (WAS), as opposed to standard CO2 technique, improved procedural pain and detection of adenomatous polyps.

Design: The WASh (Water-Assisted Sigmoidoscopy) trial was a multicentre, single-blind, randomised control trial for people undergoing BSS. Participants were randomised to either receive WAS or CO2 from five sites across England. The primary outcome measure was patient-reported moderate/severe pain, as assessed by patients on a standard Likert scale post procedure prior to discharge. The key secondary outcome was adenoma detection rate (ADR). The costs of each technique were also measured.

Results: 1123 participants (50% women, mean age 55) were randomised (561 WAS, 562 CO2). We found no difference in patient-reported moderate/severe pain between WAS and CO2 (14% in WAS, 15% in CO2; p=0.47). ADR was 15% in the CO2 arm and 11% in the WAS arm (p=0.03); however, it remained above the minimum national performance standard in both arms. There was no statistical difference in mean number of adenomas nor overall polyp detection rate. There was negligible cost difference between the two techniques.

Conclusion: In the context of enema-prepared unsedated screening sigmoidoscopies performed by screening-accredited endoscopists, no difference in patient-reported pain was seen when using either a CO2 or WAS intubation technique.

Trial registration number: ISRCTN81466870.

Keywords: clinical trials; colorectal cancer screening; colorectal neoplasia; gastrointesinal endoscopy.

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Conflict of interest statement

Competing interests: MDR reports personal fees from Swiss SCWeb, personal fees from Pentax, grants from Olympus and personal fees from Norgine, outside the submitted work. ZPT reports other from Creo Medical Ltd, grants from Norgine Ltd, other from Olympus KeyMed and Pentax Medical, outside the submitted work. CJR reports grant funding from ARC Medical, Norgine and Olympus Medical, and was an expert witness for ARC Medical.

Figures

Figure 1
Figure 1
Participant CONSORT flow diagram. CONSORT, Consolidated Standards of Reporting Trials; WAS, water-assisted sigmoidoscopy
See this image and copyright information in PMC

Comment in

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