The WASh Trial: water-assisted sigmoidoscopy in the English Bowel Scope Screening Programme: study protocol for a randomized multicenter trial

Abstract

Background and study aims The English National Bowel Scope Screening Programme (BSSP) invites 55-year-olds for a one-off, unsedated flexible sigmoidoscopy (FSIG). Data from BSSP participant-reported experience studies shows 1 in 3 participants report moderate or severe discomfort. Water-assisted colonoscopy (WAS) may improve participants’ comfort. The primary objective of this study is to ascertain if post-procedural participant-assessed pain is reduced in WAS compared with carbon dioxide (CO 2 ) insufflation, in invitees undergoing FSIG in BSSP. Patients and methods This is a multicenter, prospective, randomized, two-arm, single-blinded trial designed to evaluate the performance of WAS versus CO 2 insufflation in BSSP. Participants will be randomized to either CO 2 or WAS and will be asked to rate pain post-procedure. Key procedure-related data will be analyzed, including adenoma detection rates (ADR) and degree of sigmoid looping. A cost-effectiveness analysis of WAS versus CO 2 and a discrete choice experiment exploring preferences of participants for attributes of sigmoidoscopy will also be performed. Discussion This is the first trial in the United Kingdom (UK) to investigate the effects of WAS in a screening setting. If the trial shows WAS either reduces pain or increases ADR, this may result in a practice change to implement WAS in screening and non-screening endoscopic practice directly impacting on 256,000 people a year who will undergo BSSP FSIG by 2020. Trial funding came from National Institute for Health Research (NIHR) Research for Patient Benefit (RfPB) supported by the NIHR Clinical Research Network. The trial is actively recruiting. ID: 35866 ISRCTN: 81466870

Barriers to flexible sigmoidoscopy colorectal cancer screening in low uptake socio‐demographic groups: A systematic review

“…Early BSSP data has found one in three patients to report moderate to severe discomfort. 75 Screening modifications are thus being trialled to see if post-procedural pain is reduced when using water-assisted, rather than the current CO 2, insufflation for BSSP. 75 With regards to gender preference of medical professionals, Stoffel et al 76 investigated the preference for women to have a samegender practitioner.…”

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

“…The WASh trial was a multicentre, prospective, two-armed, randomised, single-blinded trial designed to evaluate the effectiveness of WAS in patients referred for BSS screening. 13 Our primary outcome measure was patient-reported moderate/ severe pain, using the standard BSS Likert scale recorded after their procedure. Our key secondary outcome measure was ADR.…”

“…3 The results of the logistic (binary) regression analysis (table 2) conducted on the primary outcome of patient-reported moderate or severe pain (judged immediately after the procedure) revealed no statistically significant difference between the WAS and CO 2 arms (OR=1. 13…”

Water assistance: also for sigmoidoscopy?

“…In this issue of Endoscopy International Open, the protocol for an ongoing randomized controlled trial (RCT) is described [1]. The primary objective is to ascertain if procedural pain, assessed post-procedure and prior to discharge, is reduced in water-assisted sigmoidoscopy (WAS) compared to carbon dioxide (CO 2 ) insufflation in people undergoing unsedated flexible sigmoidoscopy as part of the United Kingdom Bowel Scope Screening Program (BSSP).…”

“…The WAS technique (water infusion based on endoscopist discretion, suction of infused water as needed or as per usual practice during withdrawal) [1] appears to resemble WI (▶ Table 1). Data in the literature would suggest that WAS may need the addition of standardized water suction during insertion to achieve effectiveness as optimal as WE in minimizing insertion pain or increasing adenoma detection.…”