Comparative Evaluation of the Efficacy of Polyethylene Glycol With Ascorbic Acid and an Oral Sulfate Solution in a Split Method for Bowel Preparation: A Randomized, Multicenter Phase III Clinical Trial

Efficacy and safety of oral sodium sulfate tablet compared with 1-L polyethylene glycol plus ascorbate: a prospective, randomized, endoscopist-blinded trial

BACKGROUND AND AIM

Low-volume bowel preparation solutions, including 1-L polyethylene glycol plus ascorbate (PEG-A), have been developed to improve tolerability. The oral sodium sulfate tablet (OST) is a new agent with simethicone as a preloaded component. We investigated the efficacy, safety, and tolerability of OST compared to 1-L PEG-A.

METHODS

A single-center, prospective, controlled study was performed with randomization into the OST (group A) and 1-L PEG-A (group B) groups. Bowel preparation efficacy was assessed on the Boston Bowel Preparation Scale (BBPS) and Bubble Scale. Safety and tolerability were evaluated using a questionnaire and laboratory examination.

RESULTS

Final analysis was performed on 171 patients (group A: 87, group B: 84). The proportion of bowel preparation success (BBPS ≥ 2 for each colonic segment) in group A was not inferior compared to group B (95.4% vs 96.4%, P = 0.736, 1-sided 97.5% lower confidence limit -7.0%). The adenoma detection rate was not different (59.6% vs 41.9%; P = 0.087). The bubble scale was better in group A (0.2 ± 0.9 vs 1.9 ± 1.7, P < 0.001). All adverse events were mild in both groups. Nausea was less frequent in group A (14.9% vs 38.1%, P = 0.001). Overall satisfaction was better in group A (8.1 ± 2.1 vs 6.4 ± 2.8, P < 0.001). No clinically significant laboratory abnormality developed in both groups. These findings were similarly shown in old patients ≥65 years.

CONCLUSIONS

Both OST and 1-L PEG-A were efficacious, safe, and tolerable for bowel preparation of colonoscopy. The OST showed fewer bubbles and slightly better tolerability.

Comparison of the efficacy and safety of an oral sulfate solution and 3-L polyethylene glycol on bowel preparation before colonoscopy: a phase III multicenter randomized controlled trial

BACKGROUND AND AIMS

Adequate bowel preparation is crucial for clear mucosal visualization during colonoscopy. We aimed to comprehensively compare oral sulfate solution (OSS) and 3-L split-dose polyethylene glycol (PEG) for bowel preparation before colonoscopy.

METHODS

This randomized, active-controlled, noninferiority study was performed in 10 medical centers. Eligible subjects were enrolled to receive OSS or 3-L PEG in a split-dose regimen. The quality of bowel preparation, adverse reactions, and acceptability were evaluated. The quality of bowel preparation was evaluated using the Boston Bowel Preparation Scale. Safety was evaluated by adverse reactions. The study population was divided into the full analysis set (FAS), the safety set, the modified FAS (mFAS), and the per-protocol set (PPS).

RESULTS

Three hundred forty-eight potentially eligible subjects were enrolled. Three hundred forty-four subjects were included in the FAS and safety set, 340 subjects were included in the mFAS, and 328 subjects were included in the PPS. Adequate bowel preparation of the OSS was not inferior to 3-L PEG in the mFAS (98.22% vs 97.66%) and the PPS (98.17% vs 98.78%). There was no significant difference in acceptability between the 2 groups (94.74% vs 94.80%, P = .9798). Overall adverse reactions were similar (50.88% vs 44.51%, P = .2370) between the 2 groups.

CONCLUSIONS

The split-dose OSS regimen was not inferior to the split-dose 3-L PEG regimen for the quality of bowel preparation in a Chinese adult population. The safety and acceptability of the 2 groups were similar. (Clinical trial registration number: NCT05465889.).

Preoperative mechanical bowel preparation using conventional versus hyperosmolar polyethylene glycol-electrolyte lavage solution before laparoscopic resection for colorectal cancer (TLUMP test): a phase III, multicenter randomized controlled non-inferiority trial

BACKGROUND

A hyperosmolar ascorbic acid-enriched polyethylene glycol-electrolyte (ASC-PEG) lavage solution ensures excellent bowel preparation before colonoscopy; however, no study has demonstrated the efficacy of this lavage solution before surgery. This study aimed to establish the non-inferiority of ASC-PEG to the standard polyethylene glycol-electrolyte solution (PEG-ELS) in patients undergoing laparoscopic resection for colorectal cancer.

METHODS

This was a prospective, single-blind, multicenter, randomized, controlled, non-inferiority clinical trial. Overall, 188 patients scheduled for laparoscopic colorectal resection for single colorectal adenocarcinomas were randomly assigned to undergo preparation with different PEG solutions between August 2017 and April 2020 at four hospitals in Japan. Participants received ASC-PEG (Group A) or PEG-ELS (Group B) preoperatively. The primary endpoint was the ratio of successful bowel preparations using the modified Aronchick scale, defined as "excellent" or "good."

RESULTS

After exclusion, 86 and 87 patients in Groups A and B, respectively, completed the study, and their data were analyzed. ASC-PEG was not inferior to PEG-ELS in terms of effective bowel preparation prior to laparoscopic colorectal resection (0.93 vs. 0.92; 95% confidence interval, - 0.078 to 0.099, p = 0.007). The total volume of cleansing solution intake was lower in Group A than in Group B (1757.0 vs. 1970.1 mL). Two and three severe postoperative adverse events occurred in Groups A and B, respectively. Patient tolerance of the two solutions was almost equal.

CONCLUSIONS

ASC-PEG is effective for preoperative bowel preparation in patients undergoing laparoscopic resection for colorectal cancer and is non-inferior to PEG-ELS.

Cleaning effect and tolerance of 16 bowel preparation regimens on adult patients before colonoscopy: a network meta-analysis

PURPOSE

Colonoscopy is the gold standard for the diagnosis of colorectal cancer (CRC). Before a colonoscopy, an adequate bowel preparation (BP) is required. Currently, more novel regimens with different effects have been proposed and used successively. This network meta-analysis aims to compare the cleaning effects and patients' tolerability of several BP regimens.

METHODS

We performed a network meta-analysis of randomized controlled trials including sixteen kinds of BP regimens. We searched PubMed, Cochrane Library, Embase, and Web of Science databases. The outcomes of this study were bowel cleansing effect and tolerance.

RESULTS

We included a total of 40 articles with 13,064 patients. For the primary outcomes, polyethylene glycol (PEG) + ascorbic acid (Asc) + simethicone (Sim) (OR, 14.27, 95%CrI, 2.68-127.87) regimen is ranked first in Boston Bowel Preparation Scale (BBPS). PEG + Sim (OR, 2.0, 95%CrI 0.64-6.4) regimen is ranked first in Ottawa Bowel Preparation Scale (OBPS), but without significant differences. For the secondary outcomes, PEG + Sodium Picosulfate/Magnesium Citrate (SP/MC) (OR, 4.88e + 11, 95%CrI, 39.56-1.82e + 35) regimen is the best in cecal intubation rate(CIR). PEG + Sim (OR,1.5, 95%CrI, 1.0-2.2) regimen is ranked first in adenoma detection rate(ADR). Senna (OR, 3.23, 95%CrI, 1.04-9.97) and SP/MC (OR, 249.91, 95%CrI, 78.49-958.19) regimens are ranked first in abdominal pain and willingness to repeat, respectively. There is no significant difference in cecal intubation time (CIT), polyp detection rate (PDR), nausea, vomiting, and abdominal bloat.

CONCLUSION

PEG + Asc + Sim regimen is more effective at cleaning the bowel. PEG + SP/MC will be helpful to increase CIR. For ADR, PEG + Sim regimen will be more helpful. In addition, PEG + Asc + Sim is the least likely to cause abdominal bloat, while Senna regimen is more likely to cause abdominal pain. Patients prefer to re-use the SP/MC regimen for bowel preparation.

Efficacy of oral sulfate tablets for bowel preparation and adenoma detection rate

BACKGROUND AND AIM

The adenoma detection rate (ADR), which is closely related to bowel preparation, is the most important factor for colonoscopy quality assessment. New oral sulfate tablets (OSTs) have been developed to improve bowel preparation compliance. This study evaluated the efficacy of OSTs in terms of the ADR and bowel preparation status.

METHODS

Medical records of subjects under the age of 65 who underwent colonoscopy from March 2019 to February 2021 were retrospectively reviewed. Polyethylene glycol with ascorbic acid (PEG-A) was used as a bowel preparation for the first half of the study period, and OSTs were used for the second half. In total, 16 971 subjects were included in the study: 9199 (54.2%) used PEG-A, and 7772 (45.8%) used OSTs. Bowel cleansing quality was assessed by the Boston Bowel Preparation Scale (BBPS).

RESULTS

The average age was 50 years. The rate of adequate bowel preparation was higher in the OST group than in the PEG-A group (97.2% vs 95.0%, P < 0.001). The mean BBPS was also higher in the OST group (8.02 vs 7.75, P < 0.001). The adenomas per colonoscopy (APC), the ADR and the sessile serrated polyp detection rate (SSPDR) were higher in the OST group than in the PEG-A group (APC 0.56 ± 1.01 vs 0.48 ± 0.91, P < 0.001; ADR 34.5% vs 30.7%, P < 0.001; SSPDR 5.2% vs 3.3%, P < 0.001).

CONCLUSIONS

Compared with PEG-A, OSTs yielded superior APC, ADRs, SSPDRs, and better bowel cleanliness. Therefore, OSTs are a good alternative for patients who have difficulty taking large-volume bowel preparation formulations.

Determination of Sodium, Potassium, and Magnesium as Sulfate Salts in Oral Preparations Using Ion Chromatography and Conductivity Detection

An ion chromatography technique with conductivity detection was selected as an analytical tool for the simultaneous indirect determination of sodium sulfate, potassium sulfate, and magnesium sulfate via their respective cations. The method was developed and validated for the quantitative assay of the inorganic salts under study in oral pharmaceutical dosage forms. Chromatographic separation was achieved on a Dionex®IonPac® CS16 column (250 × 5 mm) column using the gradient elution method. A mobile phase-A consisting of methane sulfonic acid (6.7%, v/v) in Milli-Q water, which is used together with Milli-Q water, was used as a mobile Phase-B. The flow rate was 1.2 mL/min. The retention times of sodium, potassium, and magnesium as sulfates were 7.8, 12.8, and 16.2 min, respectively. The method was validated according to ICH guidelines and showed good linearity and accuracy results within concentration ranges of 80.0–240.0, 20.0–60.0, and 4.5–13.5 ppm for sodium, potassium, and magnesium as sulfates, respectively. The relative standard deviation results for intra- and inter-day precision were less than 1.0%. The method was applied successfully for determination of the analytes under study in their mixed pharmaceutical oral solution and found suitable for their routine and stability analysis.

Oral sulfate solution benefits polyp and adenoma detection during colonoscopy: Meta-analysis of randomized controlled trials

OBJECTIVES

Although oral sulfate solution (OSS) has been revealed to be not only safe and efficacious but also noninferior to polyethylene glycol with ascorbic acid (PEG + ASC), it is unclear whether OSS can ultimately increase the polyp detection rate (PDR) and adenoma detection rate (ADR). We performed this meta-analysis to estimate the effect of OSS on PDR and ADR during colonoscopy.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library to identify relevant randomized controlled trials (RCTs) investigating the comparative effect of OSS versus PEG + ASC on the PDR and ADR during colonoscopy. Cecal intubation time (CIT), cecal intubation rate (CIR), and bowel preparation score were also evaluated. Review Manager (RevMan) version 5.3.0 was used to perform statistical analysis.

RESULTS

Eight RCTs involving 2059 patients fulfilled the selection criteria. Meta-analysis suggested that OSS significantly increased the PDR (47.34% vs. 40.14%, risk ratio [RR] 1.13, 95% confidence interval [CI] 1.03-1.24, P = 0.01) and ADR (44.60% vs. 38.14%, RR 1.17, 95% CI 1.03-1.33, P = 0.01) during colonoscopy. Subgroup analysis showed that the beneficial effects of OSS on PDR and ADR were consistent among patients with mean age >55 years and with body mass index <25 kg/m² receiving outpatient colonoscopy, morning colonoscopy, and the 2-L bowel preparation protocol. Meanwhile, patients receiving OSS had a beneficial bowel preparation score.

CONCLUSION

Compared with polyethylene glycol-based regimens, the OSS bowel preparation regimen significantly increased the PDR and ADR in patients undergoing colonoscopy.

Oral sulfate solution versus low-volume polyethylene glycol for bowel preparation: Meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Oral sodium sulfate (OSS) solution and low-volume polyethylene glycol-based solutions are two of the more common low-volume purgatives used as colonoscopy preparations. Data on how these different low-volume solutions compare are mixed. Our aim was to conduct a meta-analysis of randomized controlled trials (RCTs) to compare OSS with low-volume polyethylene glycol solutions (PEG) plus ascorbic acid (PEG + Asc) solution with respect to (i) satisfactory bowel preparation, (ii) excellent bowel preparation, and (iii) tolerability.

METHODS

Studies were identified by searching 10 medical databases for reports published from 1974 until 2019. Only fully published RCTs comparing OSS and low-volume PEG-based products with regard to overall satisfactory bowel preparation were included. Pooling was conducted by both fixed-effects and random effects models; results are presented from the random effects model when heterogeneity was significant.

RESULTS

Seven studies (involving 2049 subjects) met the inclusion criteria. There was no difference between OSS and PEG + Asc with respect to adequate bowel preparation (risk ratio [RR] 1.02 [0.99-1.06]; P = 0.16). OSS did result in a higher chance of excellent bowel preparation (RR 1.18 [1.06-1.31]; P = 0.03). OSS was associated with a 30% increased risk of nausea (RR 1.35 [1.03-1.77]; P = 0.03) and more than double the risk of vomiting (RR 2.30 [1.63-2.23]; P < 0.05) compared with PEG + Asc. Begg's funnel plot indicated low probability of publication bias.

CONCLUSIONS

Individuals at low risk of inadequate bowel preparation who use OSS for bowel preparation are more likely to achieve excellent bowel preparation, but are more likely to experience nausea and vomiting than are individuals using low-volume PEG-based solutions.

Randomized trial of oral sulfate solution versus polyethylene glycol-ascorbic acid for bowel cleansing in elderly people

BACKGROUND AND AIM

The efficacy and safety of the recently introduced low-volume purgatives in elderly people are not well known. Therefore, in this trial, we aimed to evaluate and compare the efficacy of two low-volume agents, oral sulfate solution (OSS) and 2-L polyethylene glycol with ascorbic acid (PEG-Asc), in elderly people.

METHODS

A prospective, randomized, single-blinded, multicenter, non-inferiority trial was performed at three university-affiliated hospitals in South Korea. Outpatients aged 65-80 years, who underwent elective colonoscopy, were enrolled. The primary outcome was the rate of adequate bowel preparation assessed using the Boston Bowel Preparation Scale.

RESULTS

A total of 199 subjects were randomized into the OSS (n = 99) or the 2-L PEG-Asc (n = 100) group. Of them, 189 subjects were included in the analysis of the primary outcome (OSS group 95 vs PEG-Asc group 94). The proportion of adequate bowel preparation was 89.5% (85/95) in the OSS group and 93.6% (88/94) in the 2-L PEG-Asc group. OSS was not inferior to 2-L PEG-Asc according to the prespecified non-inferiority margin of -15% (95% confidence interval for the difference, -12.1 to 3.8). Vomiting (11.6% vs 2.1%) and thirst (24.2% vs 11.7%) were more common in the OSS group than in the 2-L PEG-Asc group.

CONCLUSIONS

OSS is an effective low-volume purgative that is non-inferior to 2-L PEG-Asc in elderly people. Both the low-volume agents were identified to be well tolerated and safe in the healthy elderly population.

Effectiveness of concomitant use of green tea and polyethylene glycol in bowel preparation for colonoscopy: a randomized controlled study

BACKGROUND

Polyethylene glycol solution (PEG) is widely used for bowel preparation prior to colonoscopies. However, patients often exhibited adverse events as nausea, vomit and distention due to its uncomfortable tastes and potential side affects. This study aimed to evaluate the effectiveness and safety of concomitant use of green tea (GT) with PEG in bowel preparation prior to colonoscopy.

METHODS

This was a prospective, randomized controlled study. It was conducted at an outpatient setting of colorectal surgery in a tertiary hospital. Patients aged 18 through 80 who were scheduled to undergo colonoscopy between August 2015 and February 2016 were randomly assigned into two groups, admitting either 2 L-PEG solutions with 1 L GT liquids or 2 L-PEG solutions only for bowel preparation. Admitted doses of PEG solutions, taste evaluation, adverse reactions (nausea and vomiting, distention and abdominal pain) were investigated by questionnaires. The bowel cleanliness of each patient was evaluated according to the Aronchick indicators.

RESULTS

A total of 116 patients were enrolled in this study (PEG+GT 59, PEG 57). Full compliances were achieved in 93.2% patients of group PEG+GT and 59.6% of group PEG (p < 0.001). Mean Aronchick scale between two groups were 2.0 ± 0.9 versus 2.2 ± 0.7 respectively (PEG+GT vs PEG, p = 0.296). Rates of adverse events as nausea and vomiting, abdominal pain in bowel preparation were significantly different between two groups (55.9% vs 77.2%, p = 0.015 and 13.6% vs 33.3%, p = 0.012). Patients in group PEG+GT who have probabilities to receive repeating colonoscopy had a higher willingness to accept PEG+GT again for bowel preparation, compared with PEG group (94.9% vs 57.9%, p < 0.001).

CONCLUSIONS

Concomitant use of green tea and polyethylene glycol may effectively reduce incidence of adverse events, increase compliances, with comparable bowel cleanliness in bowel preparation.

TRIAL REGISTRATION

This trial was retrospectively registered on Feb 1st, 2019 (ChiCTR1900021178).

High-quality colon cleansing and multiple neoplasia detection with 1L NER1006 versus mid-volume options: Post hoc analysis of phase 3 clinical trials

Background and study aims  Multiple neoplasia increase the risk of colorectal cancer. High-quality cleansing may improve adenoma detection. We assessed whether a new bowel preparation can improve colon cleansing and multiple lesion detection. Patients and methods  This post hoc analysis of two randomized clinical trials in Europe and the US assessed the per study and combined cleansing efficacy of overnight split dosing with (preparation + clear fluids) 1 + 1 L polyethylene glycol (PEG) NER1006 versus 2 + 1 L PEG + ascorbate (2LPEG) or 1 + 2 L oral sulfate solution (OSS) combined. Treatment-blinded central readers assessed cleansing quality using the Harefield Cleansing Scale (HCS). Patients with full segmental scoring were included. HCS segmental scores 0-4 (high-quality = HCS 3-4) were analyzed for NER1006 versus 2LPEG/OSS. Mean number of polyps or adenomas per patient (MPP/MAP) was calculated for treatments in patients with at least one polyp or adenoma. Results  In 1037 patients, NER1006 attained a greater rate of HCS 3 scores (29 % vs. 20 %; P  < 0.001) and HCS 4 scores (20 % vs. 17 %; P  = 0.007) versus 2LPEG/OSS. More polyps (678 versus 585) and adenomas (397 versus 331) were detected with NER1006 (N = 517) versus 2LPEG/OSS (N = 520). In all neoplasia-positive patients, with increasing minimal per-patient neoplasia multiplicity from 1 to 10, NER1006 numerically improved MPP (difference ± SE: 0.48 ± 0.24 to 3.89 ± 3.37) and MAP (0.47 ± 0.26 to 7.50 ± 9.00) versus 2LPEG/OSS. Conclusions  Low-volume NER1006 enhances high-quality cleansing versus medium-volume 2LPEG or OSS, individually and when combined. NER1006 may consequently facilitate the detection of multiple neoplasia in patients.

Comparison of Oral Sulfate Solution and Polyethylene Glycol Plus Ascorbic Acid on the Efficacy of Bowel Preparation

Background/Aims

The quality of bowel preparation is one of the quality indicators for colonoscopy. The aim of this study was to compare the efficacy of oral sulfate solution (OSS) and polyethylene glycol plus ascorbic acid (PEG-AA) for bowel preparation.

Methods

The study involved 167 patients who underwent diagnostic colonoscopies. Inadequate bowel preparation was defined as any score of ≤1 in each colon section based on the Boston Bowel Preparation Scale. Multivariate logistic regression was used to compare the efficacy of OSS and PEG-AA. Subgroup analyses were performed based on patient characteristics.

Results

Overall, 106 (63.5%) patients received OSS, and 61 (36.5%) patients received PEG-AA. The rate of inadequate bowel preparation was 12.3% in patients receiving OSS and 32.8% in patients receiving PEG-AA (p=0.001). OSS (odds ratio [OR] = 0.26; p=0.003) and morning examination (OR=0.11; p=0.038) were significantly associated with efficient bowel preparation. The efficacy of OSS compared with PEG-AA was only significant in patients ≥50 years of age vs. <50 years of age (OR=0.13; p=0.001 vs. OR=0.96; p=0.959) and female vs. male patients (OR=0.06; p=0.002 vs. OR=0.58; p=0.339).

Conclusions

OSS was significantly more efficient for bowel preparation than PEG-AA, especially in patients ≥50 years of age and female patients. Morning examination led to a good quality of bowel preparation, irrespective of the preparation regimen.

Improved high-quality colon cleansing with 1L NER1006 versus 2L polyethylene glycol + ascorbate or oral sulfate solution

BACKGROUND & AIMS

Colonoscopy requires bowel cleansing for gut mucosa visualization; high-quality cleansing facilitates lesion detection. NER1006 is a 1L polyethylene glycol (PEG) bowel preparation. This post hoc analysis of two randomized trials investigated cleansing efficacy assessed, as in clinical practice, by site endoscopists.

METHODS

Patients received NER1006, 2L PEG + ascorbate (2LPEG), or oral sulfate solution (OSS) as a 2-day evening/morning regimen (N2D) or NER1006 morning-only dosing (N1D). Treatment-blinded site endoscopists assessed cleansing using the Harefield Cleansing Scale (HCS). Analyses were conducted in a modified full analysis set, including (mFAS; n = 1378) or excluding (mFAS2; n = 1319) imputed failures, and in patients with 100% treatment adherence (mFAS100; n = 1047). Overall cleansing success (HCS grade A/B), overall high-quality cleansing (HCS grade A), and high-quality segments (HCS 3-4) per treatment population were analyzed.

RESULTS

Overall cleansing success was higher with N2D than 2LPEG (92.7-97.5% vs. 87.9-93.0%), and more patients had overall high-quality cleansing with N2D and N1D than 2LPEG (68.0-72.1% and 64.0-68.4% vs. 50.7-56.0%). Without imputed failures, N2D delivered more overall high-quality cleansing than OSS (74.5-77.3% vs. 67.8-69.8%). More high-quality segments were demonstrated with N2D and N1D versus 2 LPEG (82.5-87.1% and 79.4-84.4% vs. 70.4-76.3%) and with N2D versus OSS (82.7-89.5% vs. 78.1-84.4%).

CONCLUSION

When assessed by site endoscopists, NER1006 delivers greater high-quality cleansing than 2LPEG or OSS.

Comparison Between an Oral Sulfate Solution and a 2 L of Polyethylene Glycol/Ascorbic Acid as a Split Dose Bowel Preparation for Colonoscopy

BACKGROUND/AIMS

This study aimed to compare the efficacy and tolerability of an oral sulfate solution (OSS) versus 2 L of polyethylene glycol/ascorbic acid (2L-PEG/Asc) for bowel cleansing before colonoscopy.

METHODS

A prospective, single-center, single-blinded, noninferiority, randomized, controlled trial was performed. The primary outcome was the rate of successful bowel cleansing, evaluated using the Boston Bowel Preparation Scale (BBPS). Secondary outcomes were examination time, polyp, and adenoma detection rate (PDR and ADR), tolerability, and safety. Ease of use, palatability, intention to reuse, and satisfaction were evaluated using a questionnaire.

RESULTS

A total of 187 participants were randomized to receive either OSS (n=93) or 2L-PEG/Asc (n=94). Successful bowel cleansing was achieved in 86.0% (80/93) of the OSS group, which was noninferior to the 2L-PEG/Asc group (88.3%, 83/94), with a difference of -2.3% by ITT analysis [95% confidence interval (CI) -12.0 to +7.4]. The withdrawal time of the OSS group was significantly shorter than that of the 2L-PEG/Asc group (11.8±5.2 vs. 14.3±8.5; P=0.016). Ease of use, palatability, intention to reuse, and satisfaction were similar between the 2 groups. Adverse events were also similar between the 2 groups. Mucosal erythema (4.3%) and aphthous lesions (2.1%) were found only in the 2L-PEG/Asc group.

CONCLUSIONS

OSS was as effective as 2L-PEG/Asc for successful bowel cleansing and had acceptable tolerability. OSS is a promising and safe low-volume preparation alternative for colonoscopy. (Clinical trial registration number: NCT02761213.).