Efficacy and tolerability of high and low-volume bowel preparation compared: A real-life single-blinded large-population study

Abstract

BACKGROUND Low-volume preparations for colonoscopy have shown similar efficacy compared to high-volume ones in randomized controlled trials (RCT). However, most RCTs do not provide data about clinical outcomes including lesions detection rate. Moreover, real-life comparisons are lacking. AIM To compare efficacy (both in terms of adequate bowel preparation and detection of colorectal lesions) and tolerability of a high-volume (HV: 4 L polyethylene glycol, PEG) and a low-volume (LV: 2 L PEG plus bisacodyl) bowel preparation in a real-life setting. METHODS Consecutive outpatients referred for colonoscopy were prospectively enrolled between 1 December 2014 and 31 December 2016. Patients could choose either LV or HV preparation, with a day-before schedule for morning colonoscopies and a split-dose for afternoon procedures. Adequate bowel preparation according to Boston Bowel Preparation Scale (BBPS), clinical outcomes including polyp detection rate (PDR), adenoma detection rate (ADR), advanced adenoma detection rate (AADR), sessile/serrated lesion detection rate (SDR) and cancer detection rate and self-reported tolerability of HV and LV were blindly assessed. RESULTS Total 2040 patients were enrolled and 1815 (mean age 60.6 years, 50.2% men) finally included. LV was chosen by 52% of patients (50.8% of men, 54.9% of women). Split-dose schedule was more common with HV (44.7% vs 38.2%, P = 0.005). High-definition scopes were used in 33.4% of patients, without difference in the two groups ( P = 0.605). HV and LV preparations showed similar adequate bowel preparation rates (89.2% vs 86.6%, P = 0.098), also considering the two different schedules (HV split-dose 93.8% vs LV split-dose 93.6%, P = 1; HV day-before 85.5% vs LV day-before 82.3%, P = 0.182). Mean global BBPS score was higher for HV preparations (7.1 ± 1.7 vs 6.8 ± 1.6, P < 0.001). After adjustment for sex, age and indications for colonoscopy, HV preparation resulted higher in PDR [Odds ratio (OR) 1.32, 95%CI: 1.07-1.63, P = 0.011] and ADR (OR 1.29, 95%CI 1.02–1.63, P = 0.038) and comparable to LV in AADR (OR 1.51, 95%CI 0.97-2.35, P = 0.069), SDR and cancer detection rate. The use of standard-definition colonoscopes was associated to lower PDR (adjusted OR 1.59, 95%CI: 1.22-2.08, P < 0.001), ADR (adjusted OR 1.71, 95%CI: 1.26–2.30, P < 0.001) and AADR (adjusted OR 1.97, 95%CI: 1.09-3.56, P = 0.025) in patients receiving LV preparation. Mean Visual Analogue Scale tolerability scored equally (7, P ...

Risk factors for inadequate bowel preparation in patients using high- and low-volume cleansing products

“…LV products, either PEG- or non-PEG-based, have been introduced in order to improve patients’ acceptability and have been proven equally effective in randomized clinical trials [17–19]. We have confirmed these results in the present study population in a previous paper [15].…”

“…Incomplete assumption of the cleansing product (<75% of the prescribed dose of PEG) was more common among patients who used HV preparations (7.9% vs. 5.4%; P = 0.00318), whereas there was no difference in adherence to the low-fibre diet (10.5% vs. 11.9%; P = 0.3287). Overall, adequate bowel preparation was achieved in 87.6% of patients; as already shown in our previous study [15], there were no differences in efficacy between HV and LV preparations, either overall (89.2% vs. 86.6%; P = 0.0983) or considering the use of split or day-before regimens.…”

“…Incomplete assumption was, as expected, more common among patients who used HV preparation in our cohort. We have previously reported in the same study population [15] that the occurrence of vomiting and nausea (but not abdominal pain or bloating) is related to incomplete assumption, confirming that increasing palatability of cleansing products is a pivotal strategy to increase adherence, independently from volume of preparation.…”

“…Analysis of clinical outcomes (such as polyp and ADRs) and of patients’ self-reported tolerability were outside the purposes of the current study because they were already addressed in a previous study [15].…”

The Effects of Combined Use of Linaclotide and Polyethylene Glycol Electrolyte Powder in Colonoscopy Preparation for Patients With Chronic Constipation

“…These combined regimens are comparable to the 4L PEG regimen in terms of the efficacy of the bowel preparation and reduce the dosage of PEG. [13][14][15][16] Linaclotide is a novel, orally administered guanylate cyclase-C (GC-C) agonist that acts on intestinal epithelial cells. On the one hand, by activating GC-C/cyclic adenosine monophosphate (cAMP), it increases the phosphorylation level of protein kinase G-II (PKG-II), and by activating cystic fibrosis transmembrane conductance regulator (CFTR), it promotes the secretion of intestinal lumen liquid, softens feces, and increases the peristalsis of the stomach and intestine, thereby making defecation more frequent.…”