Digestive Endoscopy
A new low-volume isosmotic polyethylene glycol solution plus bisacodyl versus split-dose 4 L polyethylene glycol for bowel cleansing prior to colonoscopy: A randomised controlled trial

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Abstract

Background

4-L polyethylene glycol preparations are effective for colon cleansing before colonoscopy. However, large volume and unpleasant taste reduce tolerability and acceptability limiting patient compliance. A new isosmotic low-volume polyethylene glycol preparation with citrates and simethicone plus bisacodyl has been developed to improve patient compliance and tolerability.

Aim

To compare the efficacy of 2 different regimens of preparation vs a split-dose of polyethylene glycol solution.

Patients and methods

In this randomised, blinded, comparative study, 153 patients were allocated to 3 arms. Arm 1 (n = 52) received bisacodyl and 2-L polyethylene glycol with citrates and simethicone the day before the procedure. Arm 2 (n = 50) received bisacodyl the day before and 2-L polyethylene glycol with citrates and simethicone on the day of colonoscopy. Control group (n = 51) received a split-dose of 4-L polyethylene glycol. Cleansing was evaluated according to Ottawa scale.

Results

The mean Ottawa score was not different in the 3 groups. Excellent cleansing was observed more frequently in arm 2 (70%) than in controls (49%) (p < 0.05). No serious adverse events were observed in the 3 regimens. The willingness to repeat the same bowel preparation was superior in arms 1 and 2 than in controls (p < 0.001).

Conclusions

New low-volume preparations seem to be as effective as the split 4-L polyethylene glycol regimen, showing a better tolerability and acceptability.

Introduction

Colorectal cancer (CRC) is the second most common cancer as well as the second leading cause of cancer-related mortality in Europe [1]. Screening and early detection of adults >50 years old have reduced the incidence and mortality over the last 15 years. Colonoscopy, the gold standard for detection of early signs of CRC, was fundamental in achieving this important success against this cancer [2]. Bowel preparation is an important quality measure for colonoscopy. Inadequate bowel cleansing may have negative consequences for the examination, including incomplete visualisation of the colon, missed detection of lesions, procedural difficulties, prolonged procedure time and reduced interval time for follow-up with significant economic impact [3]. The ideal preparation should completely and rapidly empty the colon of any material (solid, liquid, gaseous) without any effect on the gross or microscopic appearance of the colon, not cause significant shifts of fluids or electrolytes and be well tolerated and accepted by the patient [4].

Polyethylene glycol (PEG) osmotically balanced electrolyte solutions pass through the bowel without significant absorption or secretion. These preparations are therefore a safe option in patients with serum electrolyte imbalance, acute and chronic renal insufficiency and congestive heart failure [5], [6] PEG is usually administered as a 4 L solution in order to achieve a satisfactory level of cleansing. However this large volume has been shown to reduce the tolerability and compliance of the bowel preparation [7]. Indeed, patient surveys have identified that the most critical step of the whole colonoscopy procedure is the large volume of liquid which needs to be ingested. This therefore creates a barrier to removing fear from patients and obtaining complete adhesion to screening campaigns. To overcome this limitation, low-volume preparations have been proposed. A new isosmotic low-volume sulphate-free PEG 2 L preparation with citrates and simethicone (PEG-CS) is now available to be used in combination with bisacodyl to improve tolerability, acceptability and compliance. The primary aim of our trial was to compare 2 L PEG-CS + bisacodyl tablets given either the same day or the day before with split-dose 4 L PEG in outpatients undergoing elective colonoscopy, in terms of cleansing level.

Section snippets

Patients and methods

This is a randomised, observer-blind, parallel 3-arm, active control study including consecutive outpatients undergoing routine elective colonoscopy at the Digestive Endoscopy Unit of the Catholic University of Rome. The study protocol and informed consent form were approved by the Institutional Review Board. Outpatients aged 18–85 years undergoing routine elective colonoscopy and providing written informed consent were eligible for participation in the study. Exclusion criteria were as

Results

A total of 153 patients were randomly allocated to treatments. Two patients (both in the 4 L PEG group) did not complete the study because of non-compliance and consent withdrawn (Fig. 1). The three groups were comparable for age, sex, and BMI, for clinical indications as well as performance of colonoscopy (Table 2). There were no significant differences in the proportion of patients having morning vs afternoon colonoscopy in the 3 treatment groups.

In both 2-L PEG-CS + bisacodyl groups, 3 tablets

Discussion

According to the results of this study, a new low-volume PEG-based bowel preparation plus bisacodyl tablets was at least as effective as the split-dose 4 L PEG in achieving an adequate level of bowel cleansing but was better tolerated and accepted. The same day regimen of the new combined bowel preparation had a higher rate of “excellent” bowel preparation than split-dose 4 L PEG. Both low-volume PEG regimens had better mucosal visualisation scores (i.e. less bubbles and foam obscuring the

Conflict of interest statement

The study was supported by Promefarm, Milano, Italy. Data were independently analysed by the investigators. Paola Cesaro and Guido Costamagna received a research grant from Promefarm. The other authors disclosed no financial relationship relevant to this publication.

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