Low-volume polyethylene glycol plus ascorbic acid (PEG-Asc) reduces the dosage of colonoscopic bowel preparation (BP) solution, but is still poorly tolerated. Adding laxatives to the BP solution reduces the volume of fluid required, without affecting quality. This study aimed to compare 1 L PEG-Asc plus 24 mg senna (1L-PEG/AS) and conventional 2 L PEG-Asc (2L-PEG/A) regimens on BP quality and patient tolerability.

A single-center, randomized, investigator-blinded, noninferiority trial was performed between June and August 2022. Outpatients scheduled for colonoscopy were randomized (1:1) to the 1L-PEG/AS or 2L-PEG/A group. The Boston Bowel Preparation Scale (BBPS) was used to evaluate BP quality. Adverse events and tolerability were surveyed using questionnaires.

Overall, 344 patients received 1L-PEG/AS or 2L-PEG/A regimens. The baseline characteristics and adverse events of the two groups were comparable. The 1L-PEG/AS group showed noninferior adequate BP rates compared with the 2L-PEG/A group (88% vs. 89%, P = 1.00); overall BBPS was 7.1 ± 1.5 and 7.2 ± 1.5, respectively (P = 0.39). Higher willingness to repeat the BP was observed in the 1L-PEG/AS group (85% vs. 62%, P < 0.01).

The 1L-PEG/AS regimen was comparable to the 2L-PEG/A regimen in terms of BP adequacy, requiring lower BP solution volumes, with better patient tolerance. Thus, it may be a suitable alternative to the conventional BP solution for colonoscopy. The Japan Registry of Clinical Trials (jRCT1051220043).

The accuracy of diagnosis and the safety of treatment in colonoscopy depends largely on the quality of bowel cleansing. This study aimed to compare the efficacy and adverse reactions of Polyethylene Glycol (PEG) combined with lactulose with that of PEG alone in bowel preparation before colonoscopy.

The authors searched a number of databases including EMBASE, MEDLINE, Cochrane Library, and China Academic Journals Full-text Database. The authors screened according to literature inclusion and exclusion criteria, assessed the quality of the included literature, and extracted the data. The meta-analysis of included literature used RevMan 5.3 and Stata 14.0 software.

A total of 18 studies, including 2274 patients, were enrolled. The meta-analysis showed that PEG combined with lactulose had a better efficacy (OR = 3.87, 95% CI 3.07‒4.87, p = 0.000, and I² = 36.2% in the efficiency group; WMD = 0.86, 95% CI 0.69‒1.03, p = 0.032 and I² = 0% in the BBPS score group) in bowel preparation for patients with or without constipation. Moreover, PEG combined with lactulose had fewer adverse reactions, including abdominal pain (OR = 1.42, 95% CI 0.94‒2.14, p = 0.094), nausea (OR = 1.60, 95% CI 1.13‒2.28, p = 0.009) and vomiting (OR = 1.77, 95% CI 1.14‒2.74, p = 0.011), than PEG alone. No significant reduction in the incidence of abdominal distention was observed.

PEG combined with lactulose may be a better choice for bowel preparation before colonoscopy compared with PEG alone.

The quality of bowel preparation is an extremely important determinant of colonoscopy results. However, the efficacy of senna regimens in improving bowel cleanliness is uncertain. We conducted a systematic review and meta-analysis to synthesize data on whether using a senna bowel preparation regimen enhances the bowel cleanliness. We searched Web of Science Core Collection, MEDLINE, PubMed, Embase, Cochrane Library, and Scopus databases (from the inception to August 2021). The primary efficacy outcome was bowel cleanliness. Secondary outcomes included patient compliance, tolerance, and adverse events. Eleven trials fulfilled the inclusion criteria (3,343 patients. Overall, we found no significant differences in bowel cleanliness between the senna regimen and other bowel preparation regimens (odds ratio [95% confidence interval]: 1.02 [0.63, 1.67], p = 0.93). There was significant difference in tolerance (odds ratio [95% confidence interval]: 1.66 [1.08, 2.54], p = .02) and compliance (odds ratio [95% confidence interval]: 3.05 [1.42, 6.55], p = .004). The senna regimen yielded a significantly greater proportion of no nausea (odds ratio [95% confidence interval]: 1.84 [1.45, 2.32]) and vomiting (odds ratio [95% confidence interval]: 1.65 [0.81, 3.35]). Compared with other bowel preparation regimens, the senna regimen may be effective and safe in bowel cleaning before colonoscopy, with superior compliance and tolerance.

an adequate bowel preparation is essential for good mucosal inspection during colonoscopy. This study aims to compare the efficacy of two validated oral lavage solutions for colonoscopy preparation in African patients.

a prospective observational study of patients undergoing colonoscopy in a referral endoscopy facility in Port Harcourt, Nigeria, using sodium picosulfate magnesium citrate (SPMC) and 4L split-dose polyethylene glycol (PEG). Variables collated were sociodemographic, primary indication, comorbidities, Aronchick bowel preparation scale, polyp/adenoma detection, caecal intubation and outcome. Statistical analysis was performed using IBM SPSS version 20.

one hundred and twenty-four patients received PEG prior to colonoscopy and SPMC in 175 patients. The age range was from 22 to 92 years; mean age of 53.8 ± 14.2 years for PEG group and 55.3 ± 13.2 years for SPMC group (p=0.361). There were 215 males and 84 females. An excellent/good bowel preparation scale was recorded in 77 (62%) PEG group and 130 (74.3%) for SPMC group (p=0.592). PEG was predominantly used in the early years of endoscopists practice with the odds ratio (OR) of no polyp detection in the PEG vs SPMC groups as 1.64 (confidence interval CI 1.06-2.55) versus 0.76 (CI 0.62-0.92), respectively (p=0.016). For no adenoma detection, OR was 4.18 (CI 1.12-15.60) versus OR 0.63 (CI 0.52-0.75), respectively (p=0.012).

there is similar efficacy profile using either split volume PEG or SPMC prior to colonoscopy in these African patients. Polyp and adenoma detection rates are highly dependent on the expertise of the endoscopist.

Simethicone (SIM) is a commonly used antifoaming agent in the clinic. However, it has not been clarified whether SIM can improve the quality of intestinal preparation and the detection rates of adenomas (ADR) and polyps (PDR). This systematic review and meta-analysis were carried out to mainly evaluate the effect of SIM in bowel preparation for colonoscopy.

An electronic and a manual search of the literature for studies was conducted in PubMed, EMBASE, and Web of Science in all published data before February 1, 2020. The primary outcomes were the quality of bowel preparation and the ADR and PDR. All the data were calculated using a pooled estimate of risk ratio with 95% confidence intervals, and a random-effect model was used for the calculation.

Eighteen randomized controlled trials with 7187 patients were included in this meta-analysis. Polyethylene glycol (PEG) with SIM improved colon cleansing (P<0.00001), PDR (P=0.006) and the detection rate of lesions in the right colon (P<0.00001) when compared with PEG alone. There was no difference in the ADR (P=0.68), withdrawal time (P=0.06), cecal intubation rate (P=0.98), and cecal intubation time (P=0.65) between 2 groups. The rate of abdominal bloating rate was higher in the PEG group, but there was no significant difference in vomiting (P=0.65), and abdominal pain (P=0.25).

SIM improves the quality of bowel cleanliness and PDR but not ADR. Besides, SIM improves the detection rate of lesions in the right colon and decreased abdominal bloating, but do not affect vomiting and abdominal pain or cramping.

The aim of this study was to compare the quality and tolerability of bowel preparation using split high-doses of sennosides versus split-dose polyethylene glycol (PEG).

In this prospective, randomized, and endoscopist-blinded study, 474 outpatients were included and randomly assigned to two groups: Group 1 was comprised of 237 patients receiving split high-dose (1000 mg) sennoside solutions, and group 2 included 237 patients receiving 4 L of PEG. The efficacy of the preparations was evaluated on the Boston Bowel Preparation Scale (BBPS), and compliance and adverse effects were recorded.

The quality of colon cleansing and the ease of bowel preparation were significantly better in the senna group; the mean of total BBPS scores was 7.35 in the senna group and 6.57 in the PEG group, cleansing was adequate (BBPS score ≥ 6) in 89.9% of patients taking senna, and 73.8% in the PEG group (P = 0.001). The rates of vomiting in the senna and PEG groups were 12.7% and 29.5%, nausea rates were 28.7% and 43.9%, and abdominal pain rates were 70.9% and 43%, respectively (P < 0.001). Cecal intubation rates in the senna and PEG groups were 95.4% and 86.1% (P = 0.001), and the cecal intubation times were 6.73 ± 2.84 and 5.34 ± 5.98 min, respectively (P = 0.001).

Split high-dose senna is more effective than split-dose PEG in terms of bowel preparation quality and patient compliance. The patients who received senna had significantly less vomiting and nausea but significantly more abdominal pain. Thus, senna may be used as an alternative to PEG for bowel preparation.

Appropriate bowel cleansing before colonoscopy is an important factor in increasing the detection rate of lesions. Low-volume polyethylene glycol (PEG) plus ascorbic acid (PEG-Asc) reduces the dosage of bowel preparation agent, but still presents discomfort to patients. The primary aim of the present study was to compare the efficacy of bowel cleansing between 2 L PEG-Asc (control) and 1 L PEG-Asc with bisacodyl suppository (suppository) groups, and the secondary aim was to investigate complications and tolerability between the two groups.

This was a single-center prospective randomized controlled study. We identified 168 patients scheduled for colonoscopy between August 2017 and January 2018 and randomly assigned them to the control or to the suppository groups. Efficacy of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS), and side-effects were surveyed using questionnaires.

No significant difference was detected in baseline characteristics including insertion and withdrawal times, and adenoma detection rates between the two groups. Total BBPS score was 7.93 ± 1.06 and 7.74 ± 1.02 in the control and suppository groups, respectively (P = 0.22). Incidence of abdominal pain and nausea was not statistically different, whereas that of sleep disturbance and anal discomfort was higher in the control group. (P = 0.00).

One liter PEG-Asc with bisacodyl suppository resulted in an equivalent bowel-cleansing outcome with reduced patient discomfort compared to 2 L PEG-Asc. Therefore, PEG-Asc with bisacodyl suppository represents a potential alternative and increases patient compliance with bowel preparation.

Patient compliance during bowel preparation is important for successful colonoscopy. Bowel preparation with polyethylene glycol (PEG), the most commonly used solution for cleansing, involves the unpleasant ingestion of a large amount of liquid. Sodium picosulfate magnesium citrate (SP-MC) solution is an alternative option with better palatability than PEG. Therefore, in this study, we compared the efficacy and patient tolerability among the following three bowel preparation protocols: 2 L PEG-ascorbic acid (ASc), 1 L PEG-ASc plus bisacodyl, and SP-MC 340 mL plus bisacodyl. We conducted a randomized prospective endoscopist-blinded study between August 2018 and January 2019. A total of 311 patients were randomly classified into three groups according to the above-described bowel preparation protocols. To evaluate the efficacy of bowel cleansing, we used the Boston Bowel Preparation Scale. The degree of symptoms and the patients' satisfaction with each bowel preparation method were investigated using a questionnaire completed before sedation for colonoscopy. The baseline characteristics were similar among the three groups. There was no significant difference in the bowel preparation quality among the three groups. However, the incidence of symptoms, such as abdominal fullness and pain, was significantly lower (P = 0.006 and 0.027, respectively) while the patients' satisfaction rate was significantly higher (P = 0.012) in the SP-MC plus bisacodyl group than in the two PEG groups. In this study, the efficacy of the SP-MC plus bisacodyl solution was similar to that of the PEG solutions. However, patient tolerability and satisfaction were better in the SP-MC plus bisacodyl group than in the other groups. In conclusion, the use of SP-MC plus bisacodyl bowel preparation solution might be a better method for providing good intestinal cleansing and improving patient compliance.

Colonic bubbles obscure the colonic mucosa during colonoscopy following bowel preparation with polyethylene glycol plus ascorbic acid (PEG-Asc). Simethicone is used to enhance visualization during colonoscopy. We aimed to determine the optimal timing of simethicone addition to improve bowel preparation using PEG-Asc.

This prospective, randomized study enrolled patients undergoing elective colonoscopy from April 2017 to January 2018. They were randomly assigned to one of the following three groups: PEG-Asc only (control) or simethicone addition in the morning on the day of colonoscopy (PEG-S1) or in the evening of the day prior to colonoscopy (PEG-S2). The primary outcome was the quality of colon cleansing, and the secondary outcomes were the adenoma detection rate (ADR), polyp detection rate (PDR), and diminutive (≤ 5 mm) ADR.

In total, 240 patients were randomly allocated to the three groups; six patients were withdrawn. Of the 234 patients evaluated, 78, 79, and 77 were allocated to the control, PEG-S1, and PEG-S2 groups, respectively. The bubble scores of all colonic segments were lowest in the PEG-S2 group. There was no significant difference in ADR or PDR among the three groups. However, the diminutive ADR was significantly higher in the PEG-S2 group compared to the other two groups (control 5.1% vs. PEG-S1 8.9% vs. PEG-S2 20.8%; P = 0.009).

Addition of simethicone to PEG-Asc at the optimal time prevents the formation of air bubbles and so improves the quality of bowel preparation, especially enhancing diminutive ADR.

Simethicone is an adjunct frequently used during bowel preparation before colonoscopy and currently there is no consensus on whether it should be recommended in standard bowel preparation. We performed a systematic review and meta-analysis to determine the effect simethicone has on bowel cleanliness, adenoma detection rate (ADR), and tolerability.

We searched the literature for studies that compared colon cleansing of patients that received standard bowel preparation alone and in combination with simethicone prior to colonoscopy. The primary outcomes were colon cleanliness, ADR, and tolerability.

Sixteen randomized controlled trials with 5630 patients were included in meta-analysis. Overall, polyethylene glycol (PEG) with simethicone improves colon cleansing compared with PEG alone (odds ratio [OR] 1.48, CI 1.11 to 1.97, P = 0.008). This improvement was seen for single dosing (OR 1.83, CI 1.20 to 2.79, P = 0.005) but not for split dosing (OR 1.32, CI 0.72 to 2.43, P = 0.38). Overall, simethicone had no effect on ADR (OR 1.22, CI 0.81 to 1.83, P = 0.33), but in patients receiving single dosing, simethicone significantly increased ADR (OR 1.96, CI 1.22 to 3.16, P = 0.005). The rates of nausea (OR 0.96, CI 0.75 to 1.24, P = 0.75), vomiting (OR 1.00, CI 0.69 to 1.44, P = 0.99), and abdominal pain (OR 0.69, CI 0.40 to 1.18, P = 0.17) were not significantly different between PEG and PEG + simethicone cohorts. For abdominal bloating, the PEG cohort had greater odds of experiencing bloating than the PEG + simethicone cohort (OR 2.33, CI 1.70 to 3.20, P < 0.00001).

Simethicone improves colon cleanliness and ADR; however, this improvement is not seen in patients receiving split-dose PEG. Furthermore, simethicone decreases abdominal bloating but has no effect on nausea, vomiting, and abdominal pain. Simethicone may be a useful bowel preparation adjunct in patients unable to receive split-dose PEG.

Colonoscopy is an important diagnostic and screening tool for colorectal cancer detection and prevention, and adequate bowel preparation is critical for successful colonoscopy. Complications related to colonoscopy, either directly or indirectly related to the procedure, are increased in elderly patients, and the risks and benefits of colonoscopy procedures need to be carefully considered in these patients. Recent studies have shown that 4 L polyethylene glycol with a split preparation is safe and effective for elderly patients, and is the preferred preparation for patients with medical comorbidities. Preparations containing sodium phosphate are generally not recommended for the elderly because of increased renal complications. In addition, a low-residue diet may aid in tolerance and willingness to undergo the procedure compared with a clear liquid diet, with comparable bowel preparation adequacy. Risk factors for inadequate bowel preparations include poor adherence to split preparation instructions or volume of solution ingested, and certain patient-related medications and comorbidities, such as diabetes, elevated body mass index, and antidepressant or narcotic use. Methods for achieving safe and adequate bowel preparations in the elderly include clear instructions, reminder calls, and case management for potential confounding patient-related factors.

Precolonoscopy bowel preparation is adequate to identify lesions larger than 5 mm about 70% to 75% of the time, but the opportunity for further improvement exists. The use of high-quality formulations with established efficacy rates of 90% or greater, identification of patients who are at increased risk of an inadequate preparation, as well as patient education and motivation to be invested in the process further improves the success of cleansing. Endoscopists should strive to achieve an adequate bowel preparation in 85% or more of patients. High-quality colonoscopy requires high-quality bowel cleansing.