Colonoscopy preparation

Comparison of oral sodium phosphate tablets and polyethylene glycol lavage solution for colonoscopy preparation: a systematic review and meta-analysis of randomized clinical trials

Objective

To systematically compare the bowel cleaning ability, patient tolerance and safety of oral sodium phosphate tablets (NaPTab) and oral polyethylene glycol electrolyte lavage solution (PEGL) to inform clinical decision making.

Methods

PubMed, Embase, CBM, WanFang Data, CNKI, and VIP databases were searched for studies that used randomized controlled trials (RCTs) to compare the roles of NaPTab and PEGL in bowel preparation before colonoscopy. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias in the included papers. A meta-analysis was performed using RevMan 5.3 software.

Results

A total of 13 RCTs were eligible for inclusion, including 2,773 patients (1,378 and 1,395 cases in the NaPTab and PEGL groups, respectively). Meta-analysis revealed no significant difference in the cleansing quality of the NaPTab and PEGL groups [RR 1.02, 95% CI (0.96-1.08), P = 0.46]. The incidence of nausea was lower in the NaPTab group than in the PEGL group [RR 0.67, 95% CI (0.58-0.76), p < 0.00001]. Patients rated the taste of NaPTab higher than PEGL [RR 1.33, 95% CI (1.26-1.40), P < 0.00001]. Willingness to repeat the treatment was also higher in the NaPTab group than in the PEGL group [RR 1.52, 95% CI (1.28-1.80), P < 0.00001]. Both serum potassium and serum calcium decreased in both groups after the preparation; however, meta-analysis revealed that both minerals decreased more in the NaPTab group than in the PEGL group [MD = 0.38, 95% CI (0.13-0.62), P = 0.006 for serum potassium and MD = 0.41, 95% CI (0.04-0.77), P = 0.03 for serum calcium]. Meanwhile, serum phosphorus increased in both groups after the preparation; however, levels increased more in the NaPTab group than in the PEGL group [MD 4.51, (95% CI 2.9-6.11), P < 0.00001].

Conclusions

While NaP tablets and PEGL were shown to have a similar cleaning effect before colonoscopy, NaP tablets had improved patient tolerance. However, NaP tablets had a strong effect on serum potassium, calcium, and phosphorus levels. For patients with low potassium, low calcium, and renal insufficiency, NaP tablets should be prescribed with caution. For those at high-risk for acute phosphate nephropathy, NaP tablets should be avoided. Given the low number and quality of included studies, these conclusions will require additional verification by large high-quality studies.

Systematic review registration

10.37766/inplasy2023.5.0013, identifier: NPLASY202350013.

Association between dietary phosphorus intake and chronic constipation in adults: evidence from the National Health and Nutrition Examination Survey

BACKGROUND

Several studies suggest a link between micronutrients and constipation. However, the relationship between constipation and phosphorus has rarely been examined. The main aim of this study was to investigate the association between changes in the prevalence of chronic constipation and dietary phosphorus intake among adult respondents of the National Health and Nutritional Examination Survey (NHANES).

METHODS

Data were extracted from the NHANES database for the years 2005-2010. A total of 13,948 people were included in the analysis. Dietary information was collected using the respondents' 24-h dietary records. We conducted multiple logistic regression analyses to examine the correlation between phosphorus intake and poor bowel movement. The primary and secondary outcomes was constipation defined by stool consistency and stool frequency, respectively.

RESULTS

Following multi-variate adjustment in model III, a significant association between chronic constipation and each additional 0.1-g intake of dietary phosphorus (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.95, 1.00; P = 0.034 for stool consistency vs. OR, 0.94; 95% CI, 0.90, 0.99; P = 0.027 for stool frequency) was observed. Following multi-variate adjustment in model III, OR values and 95% CI from the second to fourth quartiles compared to the first quartile (reference group) were 0.92 (0.66, 1.27), 0.73 (0.47, 1.13), and 0.39 (0.20, 0.76), respectively, using the stool frequency definition.

CONCLUSIONS

This study revealed a negative correlation between phosphorus intake and chronic constipation. This may be due to the fact that dietary phosphorus intake is associated with softer stools and increased stool frequency. Further studies in different settings should be considered to verify these findings.

An Expert Consensus to Standardize Assessment of Bowel Cleansing for Clinical Trials of Bowel Preparations for Crohn's Disease

BACKGROUND

Despite regular need for colonoscopy in patients with Crohn's disease (CD), the efficacy and tolerability of bowel preparation (BP) agents is rarely assessed in this population. Assessing BP quality with existing scales may be challenging in CD due to presence of inflammation, bowel resection, and strictures.

AIMS

To provide recommendations for assessing BP quality in clinical trials for CD using a modified Research and Development/University of California, Los Angeles appropriateness process.

METHODS

Based on systematic reviews and a literature search, 110 statements relating to BP quality assessment in CD were developed. A panel of 15 gastroenterologists rated the statements as appropriate, uncertain, or inappropriate using a 9-point Likert scale.

RESULTS

Panelists considered it appropriate that central readers, either alone or with local assessment, score BP quality in clinical trials. Central readers should be trained on scoring BP quality and local endoscopists on performing high-quality video recording. Both endoscope insertion and withdrawal phases should be reviewed to score BP quality in each colonic segment and segments should align with endoscopic disease activity indices. The Harefield Cleansing Scale and the Boston Bowel Preparation Scale were considered appropriate. The final score should be calculated as the average of all visualized segments. Both total and worst segment scores should also be assessed.

CONCLUSIONS

We developed a framework for assessing BP quality in patients with CD based on expert feedback. This framework could support the development or refinement of BP quality scales and the integration of BP quality assessment in future CD studies.

Potential Factors Predicting Histopathologically Upgrade Discrepancies between Endoscopic Forceps Biopsy of the Colorectal Low-Grade Intraepithelial Neoplasia and Endoscopic Resection Specimens

Background

It was gradually accepted that endoscopic fragment biopsy (EFB) diagnosis cannot accurately guarantee the absence of higher-grade neoplasms within the lesion of the digestive tract. There are no well-established predictors for histopathologically upgrade discrepancies between EFB diagnosing colorectal low-grade intraepithelial neoplasia (LGIN) and endoscopic resection (ER) specimens.

Methods

A total of 918 colorectal LGINs was histopathologically diagnosed by EFB, including 162 cases with upgrade discrepancy and 756 concordant cases. We compared clinicopathological data of EFB and ER specimens between these two groups. Multivariate analysis was performed to identify predictors for this upgrade histopathology.

Results

The predominant upgrade discrepancy of LGINs diagnosed by EFB was upgrades to high-grade dysplasia (114/918, 12.4%), followed by upgrades to intramucosal carcinoma (33/918, 3.6%), submucosal adenocarcinoma (10/918, 1.1%), and advanced adenocarcinoma (5/918, 0.5%). NSAID history (OR 4.83; 95% CI, 2.27-10.27; p < 0.001), insufficient EFB number (OR 2.99; 95% CI, 1.91-4.68; p < 0.001), maximum diameter ≥ 1.0 cm (OR 6.18; 95% CI, 1.32-28.99; p = 0.021), lobulated shape (OR 2.68; 95% CI, 1.65-4.36; p < 0.001), erythema (OR 2.42; 95% CI, 1.50-3.91; p < 0.001), erosion (OR 7.12; 95% CI, 3.91-12.94; p < 0.001), surface unevenness (OR 2.31; 95% CI, 1.33-4.01; p = 0.003), and distal location of the target adenoma (OR 3.29; 95% CI, 1.68-6.41; p < 0.001) were associated with the histologically upgrade discrepancies.

Conclusion

NSAID history, insufficient EFB number, adenoma size and location, and abnormal macroscopic patterns are potential predictors for upgrade histopathology of LGINs diagnosed by EFBs. The standardization of EFB number and advanced imaging techniques could minimize the risk of neglecting the potential of this upgrade histopathology.

The unmet needs for identifying the ideal bowel preparation

Colonoscopy, since it was first employed over 60 years ago, is now the gold standard method for visualizing the mucosa of the colon, but should be of good quality. Many factors affect quality, including the type of health service organization, type of facility, staff, equipment, patient characteristics, and bowel preparation (BP). The adequacy of bowel cleansing is critical, but, unfortunately, may be inadequate in up to one‐third of procedures. The current article will present and discuss the main BPs and their drawbacks, which include patient‐dependent and procedure‐dependent factors. Cleansing quality depends on the ease/complexity of solution preparation, volume, taste, and timing of consumption. Consequently, important positive factors include simple instructions, easy preparation of the solution, low volume, pleasant taste, short drinking time (e.g. <30 min), and splitting the dose between the evening before and the morning of the colonoscopy (or even better, only one dose in the early morning to avoid night‐time problems), and short onset of action. The BP solution must also be safe with negligible side effects. Furthermore, a positive experience supports patient willingness to repeat the procedure.

Gastrointestinal endoscopy in children and adults: How do they differ?

Gastrointestinal endoscopy has grown dramatically over the past century, and with subsequent improvements in technology and anaesthesia, it has become a safe and useful tool for evaluation of GI pathology in children. There are substantial differences between paediatric and adult endoscopy beyond size, including: age-related patho-physiology and the different spectrum of diseases in children. Literature on endoscopic procedures in children is sparse but significant. The present review aims at describing the current knowledges on paediatric endoscopy practice and highlights the main areas of differences between paediatric and adult practice.

Noninferiority clinical trial comparing the bowel cleansing efficacy of sodium phosphate tablets (Quiklean®) with a polyethylene glycol/bisacodyl kit

BACKGROUND

Efficient bowel cleansing is essential for a successful colonoscopy, but the ideal cleansing agent, volume, and pharmaceutical dosage form have yet to be determined. Small-volume cleansers enhance patient compliance.

AIM

To compare the bowel cleansing efficacy of 32-tablet sodium phosphate (Quiklean^®) with 2-L polyethylene glycol (PEG)/bisacodyl (Klean-Prep/ Dulcolax^®) under identical dietary recommendations.

METHODS

This multicenter, randomized, parallel-group, noninferiority clinical trial enrolled 472 outpatients, randomized 456 subjects, and scheduled 442 subjects to undergo colonoscopy (Quiklean^® = 222 and Klean-Prep/Dulcolax^® = 220). After bowel preparation, a colonoscopist performed the colonoscopy with video recorded for rating. The primary efficacy endpoint was the bowel cleansing quality using the Aronchick Scale. The secondary endpoints were the bowel cleansing efficacy of three colon segments, tolerability and acceptability, safety using the Ottawa bowel preparation scale, questionnaires by subjects, and monitoring of adverse events.

RESULTS

Success rates (Excellent + Good) of the bowel cleansing quality by Aronchick Scale were 98.6% (n = 205) and 97.6% (n = 204) in the Quiklean^® and Klean-Prep/Dulcolax^® groups, respectively. Quiklean^® demonstrated noninferiority over Klean-Prep/Dulcolax^® in colon cleansing efficacy. Quicken showed better tolerability and acceptability in the overall experience (was rated as excellent; 24.0% vs 17.2%; P = 0.0016) and the taste of the study preparation (was rated as excellent, 23.1% vs 13.4%; P < 0.0001) than Klean-Prep/Dulcolax^®. Safety profiles did not differ between the two groups. Our data indicate that Quiklean^® is an adequate, well-tolerated bowel cleansing preparation compared with the standard comparator Klean-Prep/Dulcolax^®.

CONCLUSION

Quiklean^® is sodium phosphate tablets available on Taiwan’s market for bowel preparation; it potentially offers patients an alternative to standard large-volume bowel preparation regimens and may, therefore, increase positive attitudes toward colonoscopies and participation rates.

Colorectal Cancer Screening in the Elderly

Colorectal cancer (CRC) is a common and preventable malignancy, and routine CRC screening is recommended for average risk individuals between the ages of 50 and 75 years. Screening has been shown to decrease CRC incidence and mortality. Once patients are older than 75 years, the risk to benefit ratio of ongoing screening begins to shift. As comorbidities increase and life expectancy decreases, the future potential benefits of CRC prevention become less robust, and risk for screening-related complications grows. However, firm age cutoffs are not sufficient to guide these decisions, as there is substantial physiologic heterogeneity among individuals of the same age.

Effect of bowel preparation volume in inpatient colonoscopy. Results of a prospective, randomized, comparative pilot study

Background

Inpatient status has been shown to be a predictor of poor bowel preparation for colonoscopy; however, the optimal bowel preparation regimen for hospitalized patients is unknown. Our aim was to compare the efficacy of bowel preparation volume size in hospitalized patients undergoing inpatient colonoscopy.

Methods

This prospective, single blinded (endoscopist), randomized controlled trial was conducted as a pilot study at a tertiary referral medical center. Hospitalized patients undergoing inpatient colonoscopy were assigned randomly to receive a high, medium, or low-volume preparation. Data collection included colon preparation quality, based on the Boston Bowel Preparation Scale, and a questionnaire given to all subjects evaluating the ability to completely finish bowel preparation and adverse effects (unpleasant taste, nausea, and vomiting).

Results

Twenty-five colonoscopies were performed in 25 subjects. Patients who received low-volume preparation averaged a higher mean total BBPS (7.4, SD 1.62), in comparison to patients who received high-volume (7.0, SD 1.41) and medium-volume prep (6.9, SD 1.55), P = 0.77. When evaluating taste a higher score meant worse taste. The low-volume group scored unpleasant taste as 0.6 (0.74), while the high-volume group gave unpleasant taste a score of 2.2 (0.97) and the medium-volume group gave a score of 2.1 (1.36), P < 0.01.

Conclusion

In this pilot study we found that low-volume colon preparation may be preferred in the inpatient setting due its better rate of tolerability and comparable bowel cleanliness when compared to larger volume preparation, although we cannot overreach any definitive conclusion. Further more robust studies are required to confirm these findings.

Trial registration

The Affect of Low-Volume Bowel Preparation for Hospitalized Patients Colonoscopies. Trial registration: NCT01978509 (terminated). Retrospectively registered on November 07, 2013.

The importance of colonoscopy bowel preparation for the detection of colorectal lesions and colorectal cancer prevention

Background and study aims  Colonoscopy for colorectal cancer (CRC) screening has reduced CRC incidence and mortality and improved prognosis. Optimal bowel preparation and high-quality endoscopic technique facilitate early CRC detection. This review provides a narrative on the clinical importance of bowel preparation for colonoscopy and highlights available bowel preparations. Methods  A PubMed search was conducted through June 2019 to identify studies evaluating clinical outcomes, efficacy, safety, and tolerability associated with bowel preparation for CRC screening-related colonoscopy. Results  Selecting the optimal bowel preparation regimen is based on considerations of efficacy, safety, and tolerability, in conjunction with individual patient characteristics and preferences. Available bowel preparations include high-volume (4 L) and low-volume (2 L and 1 L), polyethylene glycol (PEG) solutions, sodium sulfate, sodium picosulfate/magnesium oxide plus anhydrous citric acid, sodium phosphate tablets, and the over-the-counter preparations magnesium citrate and PEG-3350. These preparations may be administered as a single dose on the same day or evening before, or as two doses administered the same day or evening before/morning of colonoscopy. Ingesting at least half the bowel preparation on the day of colonoscopy (split-dosing) is associated with higher adequate bowel preparation quality versus evening-before dosing (odds ratio [OR], 2.5; 95 % confidence interval [CI], 1.9-3.4). Conclusions  High-quality bowel preparation is integral for optimal CRC screening/surveillance by colonoscopy. Over the last 30 years, patients and providers have gained more options for bowel preparation, including low-volume agents with enhanced tolerability and cleansing quality that are equivalent to 4 L preparations. Split-dosing is preferred for achieving a high-quality preparation.

Sodium phosphate is superior to polyethylene glycol in constipated patients undergoing colonoscopy: a systematic review and meta-analysis

BACKGROUND

Constipation is an important and highly prevalent predictor of inadequate bowel preparation during colonoscopy. In North America, between 2 and 28% of the general population suffer from constipation. Despite the high prevalence of constipation, to our knowledge, no meta-analysis on the optimal bowel preparation for constipated patients has been performed. We aimed to systematically review the literature to determine the ideal bowel preparation regiment for patients with chronic constipation.

METHODS

A comprehensive search of electronic databases (MEDLINE, EMBASE, SCOPUS, and Web of Science) was performed. We included studies that assessed the quality of bowel preparation in constipated patients receiving different agents prior to colonoscopy. The primary outcome was colon cleanliness. Secondary outcomes included tolerability of the bowel preparation and serious adverse events.

RESULTS

Preliminary database search yielded 1581 articles after duplicates were removed. After screening of the titles and abstracts using the exclusion criteria, 358 full-text articles were retained. Full-text articles were reviewed and eight studies meeting the inclusion criteria were included for qualitative synthesis. Three randomized controlled trials identified a total of 1636 constipated patients, of whom 225 were eligible for meta-analysis. Of those, 107 (47.6%) received NaP and 118 (52.4%) received PEG. Patients receiving NaP before colonoscopy had a higher chance of a successful bowel preparation than patients receiving PEG (OR 1.87, CI 1.06 to 3.32, P = 0.003). In the studies comparing PEG to NaP, two found that NaP resulted in greater tolerability of the bowel preparation and one study found that PEG resulted in superior tolerability.

CONCLUSIONS

In chronically constipated patients undergoing colonoscopy, the use of NaP may result in superior colonic cleanliness when compared to PEG, however, quality of evidence was low. Further high-quality studies are required to delineate the optimal bowel preparation in patients with constipation.

Low-Volume Polyethylene Glycol Improved Patient Attendance in Bowel Preparation Before Colonoscopy: A Meta-Analysis With Trial Sequential Analysis

Background: Polyethylene glycol (PEG) has been regarded as the primary recommendation for bowel preparation before colonoscopy. However, a conclusive conclusion has not yet been generated.

Aim: We performed this updated meta-analysis to further investigate the comparative efficacy and safety of low volume preparation based on PEG plus ascorbic acid related to 4L PEG.

Methods: A systematic search was conducted to retrieve potential randomized controlled trials (RCTs) in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) from January 2000 to April 2018. Two independent searchers critically searched all potential citations, extracted data, and appraised risk of bias accordingly. Moreover, we used the STATA 12.0 and trial sequential analysis (TSA) 0.9 to complete all analyses.

Results: A total of 13 RCTs enrolling 3,910 patients met inclusion criteria. Meta-analysis based on PP analysis indicated that compared to standard volume PEG regime, low volume regime improved patient compliance RR = 1.01; 95% CIs = 1.00, 1.03; P = 0.143 (≥75% intake); RR = 1.07; 95% CIs = 1.00, 1.14; P = 0.046 (100% intake), the willingness to repeat the same regime (RR = 1.30; 95% CIs = 1.07, 157; P = 0.007), and patient acceptability (RR = 1.18; 95% CIs = 1.07, 1.29; P = 0.001), and decreased the overall adverse events (RR = 0.86; 95% CIs = 0.77, 0.96; P = 0.009). However, no difference was observed between these two different solutions for bowel preparation efficacy (RR = 0.98; 95% CIs = 0.95, 1.02; P = 0.340). These all results were further confirmed by TSA.

Conclusions: The effect of low volume regime was not inferior to the standard volume PEG regime, and low volume regime was associated with better compliance when subjects ingested all the solution, willingness to repeat the same regime, higher acceptability, and lower nausea in non-selected population.

Comparative efficacy of low volume versus traditional standard volume PEG on bowel preparation before colonoscopy: Protocol for an updated meta-analysis with trial sequential analysis

INTRODUCTION

Polyethylene glycol (PEG) has been considered as the first recommendation for bowel preparation prior to colonoscopy. A previous meta-analysis suggested that low volume PEG may improve the acceptability of ingesting bowel preparation solution. However, several limitations impaired the power of findings from this published meta-analysis, such as the variation in study design of included trials and adjuvant prescriptions. Moreover, some studies related to this topic have been published recently. And thus, the aim of this updated meta-analysis is to further assess the comparative efficacy of low volume versus standard volume of PEG on bowel preparation before colonoscopy with trial sequential analysis (TSA).

METHODS AND ANALYSIS

Systematic searches will be performed to capture any potential randomized controlled trials (RCTs) investigated the comparative efficacy of low volume versus traditional standard volume PEG on bowel preparation prior to colonoscopy in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials. Moreover, we will also manually check the bibliographies of related studies and reviews so as to get additional studies. Two reviewers will independently screen the citation records, extract essential information, and appraise the risk of bias of each RCT in sequence. Finally, we will used the STATA software version 12.0 and TSA software version beta 0.9 to statistically analyze all data and test the robust of each pooled result, respectively.

RESULTS

We will submit the full-text of systematic review to a peer-review journal for publication.

CONCLUSION

This updated systematic review and meta-analysis with TSA will further assess the comparative efficacy and safety of low-volume versus traditional standard volume PEG for bowel preparation prior to colonoscopy. And then, a more comprehensive evidence body on low-volume compared to standard volume PEG in bowel preparation will be constructed.

A novel device for improving visualization in an inadequately prepared colon

BACKGROUND AND AIMS

Adequate bowel preparation is crucial for a quality colonoscopy. Poor bowel preparation can result in longer procedural times, missed adenomas, earlier repeat procedures, increase costs, and decreased patient satisfaction. Pure-Vu (MOTUS GI, Tirat Carmel, Israel) is a system that facilitates intraprocedural cleaning of a poorly prepared colon during a colonoscopy by irrigating the colon and evacuating the fluid and feces. The study aims were to evaluate Pure-Vu's cleansing capabilities and its usability and safety in a live animal colon.

METHODS

The Pure-Vu system was used by 4 experienced gastroenterologists in 35 Yorkshire cross swine (66% female) that received a reduced bowel preparation to ensure an inadequate bowel preparation at baseline. Before colonoscopy the Pure-Vu was attached to the colonoscope, and the baseline prep was assessed during insertion. The Pure-Vu system was then used to cleanse the colon and the prep then assessed after Pure-Vu use.

RESULTS

No adverse effects and no failed or prematurely terminated cases were noted. Fourteen percent of the swine colons were adequately prepped at baseline (median Boston Bowel Preparation Scale [BBPS] score = 0 [25th percentile = 0; 75th percentile = 1; interquartile range = 1]) and improved to 100% after use of Pure-Vu (Wilcoxon signed rank test P < .001) (median BBPS score = 3 [25th percentile = 3; 75th percentile = 3; interquartile range = 0]). The physicians found Pure-Vu easy and intuitive to operate.

CONCLUSIONS

The Pure-Vu system effectively cleaned inadequately prepped swine colons and proved to be easy to use. The Pure-Vu device, applied in clinical practice, may result in improved overall prep quality and a reduction in repeat examinations because of inadequately prepped colons.

Randomized clinical trial comparing fixed-time split dosing and split dosing of oral Picosulfate regimen for bowel preparation

AIM

To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.

METHODS

This is study was prospective, randomized controlled study performed at a single Institution (2013-058). A total of 204 subjects were assigned to receive one of two sodium picosulfate regimens (i.e., fixed-time split or split) prior to colonoscopy. Main outcome measurements were bowel preparation quality and subject tolerability.

RESULTS

There was no statistical difference between the fixed-time split dose regimen group and the split dose regimen group (Ottawa score mean 2.57 ± 1.91 vs 2.80 ± 2.51, P = 0.457). Cecal intubation time and physician’s satisfaction of inspection were not significantly different between the two groups (P = 0.428, P = 0.489). On subgroup analysis, for afternoon procedures, the fixed-time split dose regimen was equally effective as compared with the split dose regimen (Ottawa score mean 2.56 ± 1.78 vs 2.59 ± 2.27, P = 0.932). There was no difference in tolerability or compliance between the two groups. Nausea was 21.2% in the fixed-time split dose group and 14.3% in the split dose group (P = 0.136). Vomiting was 7.1% and 2.9% (P = 0.164), abdominal discomfort 7.1% and 4.8% (P = 0.484), dizziness 1% and 4.8% (P = 0.113), cold sweating 1% and 0% (P = 0.302) and palpitation 0% and 1% (P = 0.330), respectively. Sleep disturbance was two (2%) patients in the fixed-time split dose group and zero (0%) patient in the split dose preparation (P = 0.143) group.

CONCLUSION

A fixed-time split dose regimen with sodium picosulfate is not inferior to a split dose regimen for bowel preparation and equally effective for afternoon colonoscopy.

Comparison of Two Intensive Bowel Cleansing Regimens in Patients With Previous Poor Bowel Preparation: A Randomized Controlled Study

OBJECTIVES

Inadequate bowel cleansing is a major burden for endoscopy units. The aim of this study was to compare two intensive bowel cleansing regimens in patients with previous colonoscopy with inadequate bowel preparation.

METHODS

Patients with inadequate cleansing at index colonoscopy were randomized to 4-L split-dose polyethylene-glycol (PEG) regimen vs. 2-L split-dose PEG plus ascorbic acid (PEG+Asc) regimen. All individuals underwent a 3-day low-residue diet and received 10 mg of bisacodyl, the day before colonoscopy. Cleansing was considered to be adequate if the Boston Bowel Preparation Scale scored ≥2 at each colonic segment. A non-inferiority analysis was performed to demonstrate that colonic cleansing with 2-L PEG+Asc was not inferior to 4-l PEG, considering a non-inferiority margin of 10%.

RESULTS

Adequate bowel cleansing was significantly higher in patients assigned to 4-L PEG regimen (n=127) vs. those randomized to 2-L PEG+Asc regimen (n=129) by intention-to-treat analysis (81.1 vs. 67.4%, odds ratio (OR) 2.07, 95% confidence interval (CI) (1.163-3.689)) and by per-protocol analysis (86.6 vs. 71.7%, OR: 2.55, 95% CI: (1.316-4.922)). The study was terminated for futility after the interim analysis, because the 95% CI of the difference of proportions was 3.13-24.27% in the intention-to-treat analysis and 3.33-26.47% in the per-protocol analysis, confirming the superiority of 4-L PEG preparation.

CONCLUSIONS

After 3-day low-residue diet and oral bisacodyl before colonoscopy, colon cleansing with 4-L split-dose PEG was superior to 2-L split-dose PEG+Asc in patients with previous inadequate cleansing. (EUDRACT: 2013-002506-31, NCT02073552).

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

BACKGROUND

An adequate level of bowel preparation before colonoscopy is important. The ideal agent for bowel preparation should be effective and tolerable.

OBJECTIVE

The purpose of this study was to compare the clinical efficacy and tolerability of polyethylene glycol with ascorbic acid and oral sulfate solution in a split method for bowel preparation.

DESIGN

This was a prospective, multicenter, randomized controlled clinical trial.

SETTINGS

Outpatients at the specialized clinics were included.

PATIENTS

A total of 186 subjects were randomly assigned. After exclusions, 84 subjects in the polyethylene glycol with ascorbic acid group and 83 subjects in the oral sulfate solution group completed the study and were analyzed.

INTERVENTIONS

Polyethylene glycol with ascorbic acid or oral sulfate solution in a split method was the included intervention.

MAIN OUTCOME MEASURES

The primary end point was the rate of successful bowel preparation, which was defined as being excellent or good on the Aronchick scale. Tolerability and adverse events were also measured.

RESULTS

Success of bowel preparation was not different between 2 groups (91.7% vs 96.4%; p = 0.20), and the rate of adverse GI events (abdominal distension, pain, nausea, vomiting, or abdominal discomfort) was not significantly different between the 2 groups. In contrast, the mean intensity of vomiting was higher in the oral sulfate solution group than in the polyethylene glycol with ascorbic acid group (1.6 ± 0.9 vs 1.9 ± 1.1; p = 0.02).

LIMITATIONS

All of the colonoscopies were performed in the morning, and the subjects were offered enhanced instructions for bowel preparation. In addition, the results of tolerability and adverse effect may have a type II error, because the number of cases was calculated for confirming the efficacy of bowel preparation.

CONCLUSIONS

Oral sulfate solution is effective at colonoscopy cleansing and has acceptable tolerability when it is compared with polyethylene glycol with ascorbic acid. The taste and flavor of oral sulfate solution still need to be improved to enhance tolerability.

The impact of diet liberalization on bowel preparation for colonoscopy

Background and study aims Dietary restrictions are integral to colonoscopy preparation and impact patient satisfaction. Utilizing split-dose, lower-volume polyethylene glycol 3350-electrolyte solution (PEG-ELS), this study compared colon preparation adequacy of a low-residue diet to clear liquids using a validated grading scale. Patients and methods This was a prospective, randomized, single-blinded, single-center non-inferiority study evaluating diet the day prior to outpatient colonoscopy. Subjects were randomized to a Low-Residue diet for breakfast and lunch, or Clears only. All subjects received split dose PEG-ELS. The primary endpoint was preparation adequacy using the Boston Bowel Preparation Scale (BBPS), with adequate defined as a score > 5. Secondary endpoints included mean BBPS scores for the entire colon and individual segments, satisfaction, adverse events, polyp and adenoma detection rates, and impact on sleep and daily activities. Results Final analysis included 140 subjects, 72 assigned to Clears and 68 to Low-Residue. The Low-Residue diet was non-inferior to Clears (risk difference = - 5.08 %, P = 0.04) after adjusting for age. Mean colon cleansing scores were not significantly different overall and for individual colonic segments. Satisfaction with the Low-Residue diet was significantly greater (P = 0.01). The adenoma detection rate was not statistically significantly different between study groups, but the number of adenomas detected was significantly greater with Clears (P = 0.01). Adverse events and impact on sleep and activities did not differ significantly between diet arms. Conclusions A low-residue diet for breakfast and lunch the day prior to colonoscopy was non-inferior to clear liquids alone for achieving adequate colon cleansing when using split dose PEG-ELS.

Simethicone residue remains inside gastrointestinal endoscopes despite reprocessing

BACKGROUND

During a study designed to assess endoscope reprocessing effectiveness, a borescope was used to examine lumens and ports. Cloudy, white, viscous fluid was observed inside fully reprocessed gastroscopes and colonoscopes. This fluid resembled simethicone, which is commonly administered to reduce foam and bubbles that impede visualization during gastrointestinal endoscopy. This article describes methods used to determine whether the observed fluid contained simethicone.

METHODS

Photographs of residual fluid were taken using a borescope. Sterile cotton-tipped swabs were used to collect samples of fluid observed in 3 endoscope ports. Samples were evaluated using Fourier transform infrared spectroscopy (FTIR)-attenuated total reflection analysis.

RESULTS

Residual fluid was observed inside 19 of 20 endoscopes. Fluid photographed in 8 endoscopes resembled simethicone solutions. FTIR analysis confirmed the presence of simethicone in 2 endoscopes.

CONCLUSIONS

Fluid containing simethicone remained inside endoscopes despite reprocessing. Simethicone is an inert, hydrophobic substance that may reduce reprocessing effectiveness. Simethicone solutions commonly contain sugars and thickeners, which may contribute to microbial growth and biofilm development. Studies are needed to assess the prevalence of residual moisture and simethicone in endoscopes and determine the impact on reprocessing effectiveness. We recommend minimizing the use of simethicone pending further research into its safety.

Serum Albumin Concentrations Predict hypovolaemia Caused by Polyethylene Glycol Plus Ascorbic Acid Prior to Colonoscopy in Elderly Patients

BACKGROUND

Previous studies have confirmed the safety of polyethylene glycol plus ascorbic acid for healthy middle-aged adults but not for the elderly. The osmotic pressure of polyethylene glycol plus ascorbic acid is approximately twice that of plasma osmolality and may cause dehydration.

OBJECTIVE

In this study, we determined whether dehydration was induced in elderly patients by polyethylene glycol plus ascorbic acid, and we analysed the data obtained in order to identify predictors of dehydration.

METHODS

This was a prospective, uncontrolled, before-and-after intervention study. All patients older than 65 years who underwent colonoscopies at the Moji Medical Center were administered polyethylene glycol plus ascorbic acid prior to colonoscopy. Clinical variables before and after bowel preparation were measured and analysed statistically. A multiple linear regression analysis was performed to identify predictors of dehydration due to this procedure.

RESULTS

Eighty-three patients were assessed for eligibility, and 74 clinical variables were ultimately analysed. A significant increase in the red blood cell count (4.10 versus 4.25 × 10(6)/mm(3)), haemoglobin level (12.4 versus 13.0 g/dL) and haematocrit (38.1% versus 39.4%) suggested the presence of hypovolaemia after the procedure (P < 0.001). The serum concentration of albumin before bowel preparation was identified as the only significant predictor of hypovolaemia (β = 0.47, P = 0.0001, adjusted R (2) = 0.22).

CONCLUSION

The serum concentration of albumin before bowel preparation predicted hypovolaemia caused by polyethylene glycol plus ascorbic acid in elderly patients. Therefore, care is needed in order to prevent hypovolaemia, especially in elderly patients with hypoalbuminaemia.

TRIAL REGISTRATION

No. 000015724 (University Hospital Medical Information Network Center).

Phase II Randomized Controlled Trial of Combined Oral laxatives Medication for BOwel PREParation (COMBO-PREP study)

The combination of different laxatives at reduced volumes may benefit patients by enhancing efficacy for bowel cleansing and increasing tolerability. However, evidence regarding combined preparations is scarce. This study evaluated whether the combined preparations are associated with enhanced efficacy and tolerability. This randomized phase II study had a single-blind, parallel-arm design. Between December 2013 and September 2014, consecutive patients aged between 20 and 65 years and who required diagnostic colonoscopies were considered for inclusion. Patients were randomly allocated into 4 arms: sodium picosulfate and magnesium citrate (PMC) and polyethylene glycol (PEG) with ascorbic acid in a day-prior (PMC-PEG-DP), PMC and oral sodium phosphate (NaP) in a day-prior (PMC-NaP-DP), PMC and PEG with ascorbic acid in a split-dose (PMC-PEG-SD), and PMC and oral NaP in a split-dose (PMC-NaP-SD). Primary endpoint was the Aronchick scale, and Ottawa scale results by colon segment, patients' adverse gastrointestinal symptoms, and willingness to reuse the same agents were also recorded. Successful bowel preparation was defined as an "excellent" or "good" score on the Aronchick scale. A total of 236 patients were randomized and 229 patients received the planned colonoscopy. The rates of successful bowel preparation in the PMC-PEG-DP, PMC-NaP-DP, PMC-PEG-SD, and PMC-NaP-SD were 82.5%, 64.4%, 100%, and 100%, respectively. Excluding the failed PMC-NaP-DP group, all groups showed satisfactory rates of successful bowel preparation, and the mean Ottawa scores were significantly better in the PMC-PEG-SD and PMC-NaP-SD groups than in the PMC-PEG-DP group (P < 0.0001). The PMC-PEG-DP, PMC-NaP-DP, PMC-PEG-SD, and PMC-NaP-SD groups were similar in terms of rates of adverse gastrointestinal symptoms reported on a 5-point scale (P = 0.40) and willingness to reuse the same combined preparations (P = 0.55). PMC-PEG in a day-prior or split-dose and PMC-NaP in a split-dose were efficient and tolerable bowel preparations for colonoscopy.

Quality of bowel cleansing in hospitalized patients undergoing colonoscopy: A multicentre prospective regional study

BACKGROUND

Quality of bowel cleansing in hospitalized patients undergoing colonoscopy is often unsatisfactory. No study has investigated the inpatient or outpatient setting as cause of inadequate cleansing.

AIMS

To assess degree of bowel cleansing in inpatients and outpatients and to identify possible predictors of poor bowel preparation in the two populations.

METHODS

Prospective multicentre study on consecutive colonoscopies in 25 regional endoscopy units. Univariate and multivariate analysis with odds ratio estimation were performed.

RESULTS

Data from 3276 colonoscopies were analyzed (2178 outpatients, 1098 inpatients). Incomplete colonoscopy due to inadequate cleansing was recorded in 369 patients (11.2%). There was no significant difference in bowel cleansing rates between in- and outpatients in both colonic segments. In the overall population, independent predictors of inadequate cleansing both at the level of right and left colon were: male gender (odds ratio, 1.20 [1.02-1.43] and 1.27 [1.05-1.53]), diabetes mellitus (odds ratio, 2.35 [1.68-3.29] and 2.12 [1.47-3.05]), chronic constipation (odds ratio, 1.60 [1.30-1.97] and 1.55 [1.23-1.94]), incomplete purge intake (odds ratio, 2.36 [1.90-2.94] and 2.11 [1.68-2.65]) and a runway time >12h (odds ratio, 3.36 [2.40-4.72] and 2.53 [1.74-3.67]).

CONCLUSIONS

We found no difference in the rate of inadequate bowel preparation between hospitalized patients and outpatients.

The use of low-volume polyethylene glycol containing ascorbic acid versus 2 L of polyethylene glycol plus bisacodyl as bowel preparation for colonoscopy

OBJECTIVE

Low-volume polyethylene glycol (PEG) bowel preparations have been developed to improve compliance for colonoscopy. Our study aimed to compare the efficacy and tolerability of low-volume PEG containing ascorbic acid for colonoscopy against 2 L of PEG plus bisacodyl.

METHODS

We prospectively enrolled consecutive inpatients who had not undergone polypectomy at the index colonoscopy and were subsequently referred for polypectomy at our hospital. A total of 62 patients were randomized to receive either low-volume PEG containing ascorbic acid (n = 31) or 2 L of PEG plus bisacodyl (n = 31) as a split-dose regimen in inpatients. The efficacy of preparation was determined using the Ottawa Bowel Preparation Score (OBPS) and a 4-point scale. Adverse events, tolerability, and willingness were evaluated using a questionnaire.

RESULTS

Based on the OBPS and 4-point scale, we determined that the efficacy of low-volume PEG containing ascorbic acid was comparable to that of the 2 L of PEG plus bisacodyl (p = 0.071 for OBPS, p = 0.056 for the 4-point scale). Adverse events were comparable between the two groups (p = 1.000). A greater proportion of patients in the low-volume PEG containing ascorbic acid (90.6%) and the 2L of PEG plus bisacodyl (96.9%) were willing to repeat the same preparation for subsequent colonoscopy.

CONCLUSION

Low-volume PEG containing ascorbic acid had comparable efficacy and tolerability to 2 L of PEG plus bisacodyl, when given as a split dose, for colonoscopy in inpatients. Split-dose low-volume PEG containing ascorbic acid is a good alternative for bowel preparation for colonoscopy in inpatients.

How to predict adequate bowel preparation before colonoscopy using conventional polyethylene glycol: prospective observational study based on survey

BACKGROUND AND AIM

The present study investigated the conditions and predictive factors for adequate bowel preparation using 4-L polyethylene glycol (PEG) preparation in clinical practice.

METHODS

We conducted a prospective-survey-based observational study. The survey consisted of 14 questions that assessed the preparation method (group 1: split method for morning colonoscopy; group 2: full-volume method for same-day afternoon colonoscopy; group 3: full-volume method for next-day morning colonoscopy), dinner type and timing the day before colonoscopy, elapsed time after PEG consumption, and stool character and defecation frequency immediately before colonoscopy. Preparation status was compared using the Boston bowel preparation scale (BBPS).

RESULTS

Total of 465 surveys (391 for group 1, 55 for group 2, 19 for group 3) were conducted. Mean BBPS score was highest in group 1 and lowest in group 3 (P < 0.001). Fasting dinner before colonoscopy group showed a higher mean BBPS than the diet group; eating before 6 p.m. and a low-residue diet showed a higher mean BBPS (P < 0.05). Defecation frequency (>5 times) was related to adequate preparation in the left colon and elapsed time (<5 h) to that in the right colon (P < 0.05). Liquid stool without solid material immediately before colonoscopy was related to adequate preparation (P < 0.001).

CONCLUSION

In bowel preparation with 4-L PEG, elapsed time after PEG consumption (<5 h), defecation frequency (>5 times) and liquid stool without solid material immediately before colonoscopy were predictive factors for adequate bowel preparation just before colonoscopy.

Polyethylene Glycol Electrolyte Lavage Solution versus Colonic Hydrotherapy for Bowel Preparation before Colonoscopy: A Single Center, Randomized, and Controlled Study

This single center, randomized, and controlled study aimed to compare the effectiveness and safety of polyethylene glycol electrolyte lavage (PEG-EL) solution and colonic hydrotherapy (CHT) for bowel preparation before colonoscopy. A total of 196 eligible outpatients scheduled for diagnostic colonoscopy were randomly assigned to the PEG-EL (n = 102) or CHT (n = 94) groups. Primary outcome measures included colonic cleanliness and adverse effects. Secondary outcome measures were patient satisfaction and preference, colonoscopic findings, ileocecal arrival rate, examiner satisfaction, and cecal intubation time. The results show that PEG-EL group was associated with significantly better colonic cleanliness than CHT group, fewer adverse effects, and increased examiner satisfaction. However, the CHT group had higher patient satisfaction and higher diverticulosis detection rates. Moreover, the results showed the same ileocecal arrival rate and patient preference between the two groups (P > 0.05). These findings indicate that PEG-EL is the preferred option in patients who followed the preparation instructions completely.

Colon cleansing for colonoscopy 2013: current status

Colonoscopy requires adequate bowel cleansing to be safe and effective. There are a variety of options available. This review will focus on highlighting new products, administration techniques emphasizing the value of split-dose and same-day regimens, safety, and options for inadequate cleansing.

The impact of opiate pain medications and psychoactive drugs on the quality of colon preparation in outpatient colonoscopy

BACKGROUND

Suboptimal colon preparation is a significant barrier to quality colonoscopy. The impact of pharmacologic agents associated with gastrointestinal dysmotility on quality of colon preparation has not been well characterized.

AIMS

Evaluate impact of opiate pain medication and psychoactive medications on colon preparation quality in outpatients undergoing colonoscopy.

METHODS

Outpatients undergoing colonoscopy at a single medical centre during a 6-month period were retrospectively identified. Demographics, clinical characteristics and pharmacy records were extracted from electronic medical records. Colon preparation adequacy was evaluated using a validated composite colon preparation score.

RESULTS

2600 patients (57.3 ± 12.9 years, 57% female) met the inclusion and exclusion criteria. 223 (8.6%) patients were regularly using opioids, 92 antipsychotics, 83 tricyclic antidepressants and 421 non-tricyclic antidepressants. Opioid use was associated with inadequate colon preparation both with low dose (OR = 1.4, 95%CI 1.0-2.1, p = 0.05) and high dose opioid users (OR = 1.7, 95%CI 1.1-2.9, p = 0.039) in a dose dependent manner. Other significant predictors of inadequate colon preparation included use of tricyclics (OR = 1.9, 95%CI 1.1-3.0, p = 0.012), non-tricyclic antidepressants (OR = 1.5, 95%CI 1.1-2.0, p = 0.013), and antipsychotic medications (OR = 2.2, 95%CI 1.4-3.4, p = 0.001).

CONCLUSIONS

Opiate pain medication use independently predicts inadequate quality colon preparation in a dose dependent fashion; furthermore psychoactive medications have even more prominent effects and further potentiates the negative impact of opiates with concurrent use.

Efficacy and acceptability of sodium picosulphate/magnesium citrate vs low-volume polyethylene glycol plus ascorbic acid for colon cleansing: a randomized controlled trial

AIM

The study compared the efficacy, safety and tolerability of a low-volume picosulphate/magnesium citrate preparation with that of polyethylene glycol plus ascorbic acid (PEG + ASC) in a randomized clinical trial (RCT).

METHOD

A multicentre randomized, single-blinded study was designed. Adult outpatients undergoing colonoscopy received either picosulphate/magnesium citrate (Group 1) or PEG + ASC (Group 2). Bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS) and rated as adequate if ≥ 2 in each segment. Patient acceptance, satisfaction and related symptoms were recorded.

RESULTS

Two-hundred and eighty-five patients were included. Preparation was adequate in 75.7% of patients in Group 1 and in 76.5% of patients in Group 2. The mean BBPS scores for the entire colon and for the right colon were comparable between groups. In addition, 97.1% patients in Group 1 and 84.8% in Group 2 reported no or mild discomfort (P < 0.0003) and 97.8% and 83.4% expressed their willingness to repeat the preparation (P < 0.0001). Palatability was better in Group 1, whereas related symptoms occurred more frequently in Group 2. Regardless of which preparation was used, the split regimen was associated with better cleansing compared with the same-day method (OR = 3.39; 95% CI: 1.1-10.4; P = 0.03). Other predictors of poor cleansing were comorbidity, discomfort during preparation and incomplete (< 75%) preparation.

CONCLUSION

Both picosulphate/magnesium citrate and PEG + ASC are effective for bowel preparation. Tolerability and palatability are better for picosulphate/magnesium citrate. A split schedule is associated with higher cleansing quality also for low-volume regimens.

A new colonic lavage system to prepare the colon for colonoscopy: a retrospective study

BACKGROUND

One of the most unpleasant and sometimes difficult elements of colonoscopic examination is the bowel preparation which is usually performed 6 or more hours prior to the examination ("early" preparation), causing many patients to refrain from undergoing this procedure. We present a novel technique for bowel preparation that begins approximately 30 min prior to the introduction of the colonoscope and eliminates the need for significant pre-procedure preparation.

METHODS

The medical records of all consecutive patients who underwent colonoscopy without "early" preparation (CWEP) from May 2009 through June 2010 were retrospectively reviewed. The procedure was performed using a novel cleansing device, the "ColonoScoPrep™", with which the colon is prepared about half an hour prior to insertion of the colonoscope. The only medication required is two to three bisacodyl tablets the night before. The quality of bowel preparation was graded as excellent, good, satisfactory, or poor, and patient satisfaction was assessed according to a prospective protocol.

RESULTS

During this period, 125 patients underwent CWEP. Of these, 110 (89.4 %) patients had an excellent or good preparation, permitting complete colonoscopic examination unimpeded by fecal matter. In 11 patients, preparation was satisfactory, in 2 it was poor and in 2, colonoscopy was not completed due to unsatisfactory preparation. None of the patients suffered from abdominal pain or cramps during or after the CWEP and none had post-colonoscopy diarrhea. All patients were satisfied with the procedure.

CONCLUSIONS

Despite the fact that the study is retrospective, CWEP appears safe and easy to perform. A prospective study comparing conventional bowel preparation and CWEP is now underway.

Colonic explosion during treatment of radiotherapy complications in prostatic cancer

The use of lasers has been of great importance in the field of endoscopy and surgery for their applications in coagulation and the ability to vaporize tissue. In the 1990s, new machines were introduced based on a different technology, the argon-plasma-coagulation (APC) system. This technology causes different biological effects without direct contact. An example is the hemostasis of bleeding. In the literature, several cases of complications have been reported during endoscopic treatment with APC. In this study, we report our experience of a case with colon explosion during an APC procedure for bleeding due to radiotherapy and also review the literature on the complications of APC treatment.

Split-dosed MiraLAX/Gatorade is an effective, safe, and tolerable option for bowel preparation in low-risk patients: a randomized controlled study

OBJECTIVES

MiraLAX with Gatorade is a low-volume bowel preparation regimen that has been used widely in community practice and is anecdotally better tolerated than Golytely. Despite its widespread use, there are little data on the efficacy and tolerability of this solution and no safety data in the literature. The primary aim of this study was to compare the efficacy, safety, and tolerability of single-dosed and split-dosed regimens of MiraLAX/Gatorade with Golytely for bowel preparation before colonoscopy.

METHODS

Adults presenting for outpatient colonoscopy were screened for enrollment into this single-blinded randomized controlled trial. Patients with severe cardiac or renal disease and patients with electrolyte abnormalities were excluded. Subjects were randomized into four groups: 4 l Golytely single-dosed (Go-Si), 4 l Golytely split-dosed (Go-Sp), 238 g MiraLAX in 64 oz of Gatorade single-dosed (Mlax-Si), and MiraLAX/Gatorade split-dosed (Mlax-Sp) groups. Laboratory data including complete blood count, comprehensive metabolic panel, and osmolality were collected before the day of bowel preparation and just before the start of colonoscopy. Subjects completed a survey assessing taste and tolerability of the solution. Colonoscopies were recorded using video recording software and de-identified. Colonoscopy videos were evaluated for efficacy of cleansing by two blinded endoscopists. Two validated bowel preparation scales were used to assess bowel cleansing: the Boston Bowel Preparation Scale (BBPS; 0-9 best) and Ottawa Scale (0-14 worst).

RESULTS

A total of 222 patients were evaluated in this study (86.2% male, mean age 59.4). Of these, 57 subjects were randomized to the Go-Si group, 51 to Go-Sp group, 60 to Mlax-Si group, and 54 to Mlax-Sp group. There was no significant difference in age, gender, or timing of colonoscopy between the groups (P>0.05). Mean BBPS scores were: Go-Si=6.07, Go-Sp=8.33, Mlax-Si=6.62, and Mlax-Sp=8.01. Mean Ottawa score for the groups were: Go-Si group=6.77, Go-Sp=4.12, Mlax-Si=6.25, and Mlax-Sp=4.8. Go-Sp resulted in significantly better cleansing than Go-Si (P<0.01). Mlax-Sp resulted in significantly better cleansing than Mlax-Si (P<0.01). There was no significant difference in BBPS between Go-Sp and Mlax-Sp. There were no clinically significant electrolyte changes from baseline in any subject in any group after bowel prep (P>0.05). Subjects rated the taste and overall experience of Mlax/Gatorade preparation better than Golytely (P<0.01). In all, 96.8% of Mlax/Gatorade subjects were willing to repeat the same preparation vs. 75% for Golytely subjects (P<0.01).

CONCLUSIONS

Split-dosed MiraLAX/Gatorade was an effective, safe, and tolerable option for bowel preparation before colonoscopy in the low-risk patients in this study. MiraLAX/Gatorade appears to be more tolerable than Golytely as a bowel cleansing regimen and was the preferred agent by the patients in this study.

Bowel preparation with polyethylene glycol electrolyte solution: optimizing the splitting regimen

AIM

Quality of bowel cleansing significantly increases the shorter the time between bowel solution intake and endoscopic examination. We tested the efficacy and patient tolerability following a modified polyethylene glycol electrolyte (PEG) splitting regimen.

METHODS

This was a prospective, single-blind, randomized, study. Patients were assigned to receive either PEG 4 L the afternoon before colonoscopy or PEG 3 L the day before and 1 L 3h before the procedure the day of colonoscopy.

RESULTS

The study population consisted of 336 patients, including 168 participants in each study arm. Although the bowel preparation quality was similarly quoted as excellent/good following the split and full regimen (95.2% vs 92.8%; p=0.3), a significant (p<0.0001) shift from good towards an excellent preparation (26.8% vs 68.4%) was observed following the split regimen as compared to the full regimen (55.4% vs 37.5%). The incidence of side-effects did not differ. When patients were asked about a future preparation if needed, 69% and 31% following the split and full regimen, respectively, declared to accept again the same preparation, the difference being statistically significant (p<0.001).

CONCLUSIONS

Our data found that an excellent bowel cleansing could be frequently achieved by simply modifying the split regimen from the standard PEG 2 plus 2 L to 3 plus 1 L.

Mechanism of action and toxicities of purgatives used for colonoscopy preparation

IMPORTANCE OF THE FIELD

In developed countries, colonoscopy volume has increased dramatically over the past 15 years and is the principle method used to screen for colon cancer. Preparations used for colon cleaning have evolved over the past 30 years. Some preparations have been shown to be unsafe and are now used on a limited basis. There has been progress on limiting the volume required and on taste improvement.

AREAS COVERED IN THIS REVIEW

This review provides an account of preparations used from 1980 when PEG-based preparations became widely available, until the present day. The review highlights their mechanism of action and principle toxicities. The handling of solutes and solute-free fluid by the colon is also reviewed.

WHAT THE READER WILL GAIN

The reader will gain a perspective on the factors considered in developing colonic purgatives and the rationale for choosing selected preparations based on patient factors such as age, co-morbidities and concomitant medications.

TAKE HOME MESSAGE

Although generally safe and effective, colonic purgatives have both acute and permanent toxicities. The safest preparations utilize PEG combined with a balanced electrolyte solution. Limitations of this preparation center on the volume required and poor taste. Alternative formulations are now available; however, those using sodium phosphate have fallen out of favor due to a risk of renal toxicity.

Update on preparation for colonoscopy

Colonoscopy requires adequate bowel cleansing to be safe and effective. Current options for preparation include dietary restrictions plus cathartics and purgatives, large-volume gut lavage solutions, and sodium phosphate preparations. Gut lavage with or without a stimulant laxative is safe and effective, and traditionally is taken the evening before the procedure. Sodium phosphate formulations also provide effective cleansing, but fluid and electrolyte disturbances can occur. Recent advances include split administration of gut lavage solutions-ingesting only half of the solution the evening prior to, and the rest the morning of, the procedure. Split administration can yield adequate preparations in inpatients, traditionally a difficult group for proper cleansing. A new oral sulfate solution, when commercially available, should provide safe, effective cleaning with a lower ingested volume. This review discusses the current clinical experience of available preparation options and the efforts to make preparation for colonoscopy more tolerable.

The safety of osmotically acting cathartics in colonic cleansing

Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate, combinations of polyethylene glycol and electrolyte lavage solutions (PEG-ELS), and magnesium citrate. All these preparations give adequate cleansing results and have similar profiles in terms of the frequency and type of mild to moderate adverse effects. However, serious adverse events, such as severe hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal function and water and electrolyte balance. The available evidence indicates that PEG-ELS-based products are the safest option. Magnesium-citrate-based, hypertonic products should be administered with caution to elderly individuals and patients who are prone to develop disturbances in water and electrolyte balance. Sodium-phosphate-based products can occasionally cause irreversible kidney damage and should not be routinely used in bowel-cleansing procedures.

Effective bowel cleansing before colonoscopy: a randomized study of split-dosage versus non-split dosage regimens of high-volume versus low-volume polyethylene glycol solutions

BACKGROUND

Adequate bowel cleansing is essential for a high-quality, effective, and safe colonoscopy.

OBJECTIVES

To evaluate the degree of colon cleansing comparing split-dosage versus non-split-dosage intake of two different polyethylene glycol (PEG) volumes (low-volume PEG + ascorbic acid vs standard-volume PEG-electrolyte solution) and to identify predictors of poor bowel cleansing.

DESIGN

Single-blind, active control, randomized study.

SETTING

Tertiary-care institutions in Italy.

PATIENTS

This study involved adult patients undergoing elective colonoscopy.

INTERVENTION

Colonoscopy with different bowel preparation methods.

MAIN OUTCOME MEASUREMENTS

Degree of bowel cleansing.

RESULTS

We randomized 895 patients, and 868 patients were finally included in intention-to-treat (ITT) analysis. Overall compliance was excellent (97%) for both preparation methods. No difference in tolerability was recorded. Palatability was superior with low volume compared with high volume (acceptable or good 58% vs 51%, respectively, P < .005), independently of intake schedule. PEG plus ascorbic acid produced the same degree of cleansing as standard-volume PEG-electrolyte solution (77% vs 73.4%, respectively, within the split-dosage group and 41.7% vs 44.3%, respectively, within the non-split-dosage group). Independently of PEG volumes, the split-dosage regimen produced markedly superior cleansing results over the same-day method (good/excellent 327/435, 75.2% vs 186/433, 43.0%, P = .00001). Maximum cleansing was observed in colonoscopies performed within 8 hours from the last fluid intake versus over 8 hours from the last fluid intake (P < .001). The degree of bowel cleansing affected both cecal intubation (failed intubation 11.7% with fair/poor preparation vs 1.2% with good/excellent preparation, P = .00001) and polyp detection rates (12.2% with fair/poor vs 24.6% with good/excellent preparation, P = .001). Aborted procedures were significantly more frequent in the non-split-dosage arm (21.2% vs 6.9%, odds ratio [OR] 3.60 [2.29-5.77], P < .0001). Independent predictors of poor bowel cleansing were male sex (OR 1.45 [1.08-1.96], P = .014) and a non-split-dosage bowel preparation schedule (OR 2.08 [1.89-2.37], P = .0001).

CONCLUSION

Low-volume PEG plus ascorbic acid is as effective as high-volume PEG-electrolyte solution but has superior palatability. A split-dosage schedule is the most effective bowel cleansing method. Colonoscopy should be performed within 8 hours of the last fluid intake.