Short report: comparison of two orally administered bowel preparations for colonoscopy--polyethylene glycol and sodium picosulphate

A multicenter randomized phase 4 trial comparing sodium picosulphate plus magnesium citrate vs. polyethylene glycol plus ascorbic acid for bowel preparation before colonoscopy. The PRECOL trial

Background

Adequate bowel preparation before colonoscopy is crucial. Unfortunately, 25% of colonoscopies have inadequate bowel cleansing. From a patient perspective, bowel preparation is the main obstacle to colonoscopy. Several low-volume bowel preparations have been formulated to provide more tolerable purgative solutions without loss of efficacy.

Objectives

Investigate efficacy, safety, and tolerability of Sodium Picosulphate plus Magnesium Citrate (SPMC) vs. Polyethylene Glycol plus Ascorbic Acid (PEG-ASC) solutions in patients undergoing diagnostic colonoscopy.

Materials and methods

In this phase 4, randomized, multicenter, two-arm trial, adult outpatients received either SPMC or PEG-ASC for bowel preparation before colonoscopy. The primary aims were quality of bowel cleansing (primary endpoint scored according to Boston Bowel Preparation Scale) and patient acceptance (measured with six visual analogue scales). The study was open for treatment assignment and blinded for primary endpoint assessment. This was done independently with videotaped colonoscopies reviewed by two endoscopists unaware of study arms. A sample size of 525 patients was calculated to recognize a difference of 10% in the proportion of successes between the arms with a two-sided alpha error of 0.05 and 90% statistical power.

Results

Overall 550 subjects (279 assigned to PEG-ASC and 271 assigned to SPMC) represented the analysis population. There was no statistically significant difference in success rate according to BBPS: 94.4% with PEG-ASC and 95.7% with SPMC (P = 0.49). Acceptance and willing to repeat colonoscopy were significantly better for SPMC with all the scales. Compliance was less than full in 6.6 and 9.9% of cases with PEG-ASC and SPMC, respectively (P = 0.17). Nausea and meteorism were significantly more bothersome with PEG-ASC than SPMC. There were no serious adverse events in either group.

Conclusion

SPMC and PEG-ASC are not different in terms of efficacy, but SPMC is better tolerated than PEG-ASC. SPMC could be an alternative to low-volume PEG based purgative solutions for bowel preparation.

Clinical trial registration

[ClinicalTrials.gov], Identifier [NCT01649674 and EudraCT 2011-000587-10].

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.

A prospective randomized clinical study evaluating the efficacy and compliance of oral sulfate solution and 2-L ascorbic acid plus polyethylene glycol

BACKGROUND/AIMS

Oral sulfate solution (OSS) is an emerging cleansing agent for bowel preparation. However, data comparing OSS to other conventional bowel preparations in Asian patients are limited. Therefore, the objective of this study was to compare the efficacy and tolerability of OSS to ascorbic acid plus polyethylene glycol (AA + PEG) in Asian patients.

METHODS

This was a prospective, randomized, parallel, investigator-blind study performed in two university hospitals in Korea. Bowel preparation efficacy was evaluated using both the Ottawa Bowel Preparation Scale (OBPS) and Boston Bowel Preparation Scale (BBPS).

RESULTS

Among 173 patients, 86 received OSS while 87 received AA + PEG for bowel preparation. Total OBPS score was 2.80 ± 2.48 in the OSS group and 4.49 ± 3.08 in the AA + PEG group, indicating significantly (p < 0.001) better efficacy with OSS. Total BBPS was higher in the OSS group (7.43 ± 1.49 vs. 6.51 ± 1.76, p < 0.001), indicating superior bowel preparation quality with OSS. Preparation-related adverse events were generally acceptable. Patients receiving OSS had more nausea (1.92 ± 0.94 vs. 1.54 ± 0.76, p = 0.004) and abdominal cramping (1.45 ± 0.78 vs. 1.17 ± 0.51, p = 0.006) than those receiving AA + PEG. However, overall satisfaction and taste were similar between the two groups.

CONCLUSION

OSS had a non-inferior bowel cleansing efficacy than AA + PEG regardless of colon segment.

Effectiveness in Bowel Cleansing and Patient Tolerability of Polyethylene Glycol versus Sodium Picosulphate in Patients Undergoing Colonoscopy

INTRODUCTION

Colonoscopy is considered as a gold standard investigation for screening of colorectal cancer and other lower gastrointestinal pathologies. Adequate bowel preparation is absolutely necessary for a fruitful colonoscopy. Various bowel cleansing agents are being used for his purpose. The aim of the present study was to compare the two bowel cleansing agents: a single dose of Polyethylene Glycol (PEG) solution and a split dose of Sodium Picosulfate (Na PICOSUL) tablet with regards to cleansing efficacy and tolerability among the patients scheduled for colonoscopy.

METHODS

It is an open-label hospital-based observational study. A total of sixty-four patients were grouped randomly into two groups of bowel cleansing agents that are PEG and Na PICOSUL during the study period between 1^st December 2015 and 30^th November 2016. Patients' tolerability was evaluated using a structured questionnaire, and the bowel cleansing efficacy was evaluated using the Aronchick Bowel Preparation Scale (ABPS).

RESULTS

The group that received PEG solution was found to have better efficacy than that which received Na PICOSUL tablet (63.3% versus 29.4%, respectively, with a P value < 0.028) with excellent grade as per ABPS. The Na PICOSUL group was found better in terms of tolerability than the PEG group as nausea/vomiting was encountered significantly higher in the PEG group than in the Na PICOSUL group (43.3% versus 11.8%, respectively, with a P value < 0.01).

CONCLUSIONS

Colonic preparation with a split dose of Na PICOSUL tablet was better tolerated than the evening before regimen of PEG solution. However, PEG solution was found to be more efficacious in bowel cleansing, but procedural performance and lesion detection were similar for both agents.

Split-dose Bowel Preparation for Colonoscopy: 2 Liters Polyethylene Glycol with Ascorbic Acid versus Sodium Picosulfate versus Oral Sodium Phosphate Tablets

Background/Aims

Adequate bowel preparation is an essential factor affecting the visibility of colonic mucosa and safety of related therapeutic interventions. The aim of this study was to assess the efficacy, tolerability, and safety of three bowel preparation agents -2 L polyethylene glycol with ascorbic acid (PEGA), sodium picosulfate magnesium citrate (SPMC), and oral sodium phosphate tablet (NaP)- for morning colonoscopy.

Methods

Here, we analyzed the medical records of patients who had taken bowel preparation agents using the split-dose method and undergone colonoscopy in a single hospital. The efficacy of bowel preparation agents was evaluated using the Ottawa bowel preparation assessment tool. The safety and tolerability of the agents were assessed by measuring the renal function and electrolytes prior to and after the procedure as well as by assessing the self-reported questionnaire.

Results

Of the 365 patients (PEGA:163, SPMC: 93, NaP: 109), 98.6% ingested more than 90% of the agents. NaP showed an inferior cleansing efficacy, and serum phosphate elevation was significantly higher in the NaP group. However, the satisfaction score was lowest in the PEGA group. Age (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.92-0.99, p=0.04) and preparation agents (OR of PEGA versus NaP 5.0, 95% CI 2.28-10.97, p<0.001) (OR of SPMC versus NaP 2.73, 95% CI 1.22-6.08, p=0.01) were independently associated with bowel preparation success.

Conclusions

According to our analysis, NaP showed an inferior cleansing efficacy compared with PEGA and SPMC, which may be attributed to the complex administration method and lower water intake. However, large-volume ingestion remains unsatisfactory for patients. Detailed bowel preparation instructions could enhance bowel cleansing efficacy.

Sodium Picosulfate with Magnesium Citrate (SPMC) Plus Laxative Is a Good Alternative to Conventional Large Volume Polyethylene Glycol in Bowel Preparation: A Multicenter Randomized Single-Blinded Trial

Background/Aims

We investigated whether sodium picosulfate with magnesium citrate (SPMC) plus bisacodyl compares favorably with conventional polyethylene glycol (PEG) with respect to bowel cleansing adequacy, compliance, and safety.

Methods

We performed a multicenter, prospective, single-blinded study in outpatients undergoing daytime colonoscopies. Patients were randomized into a split preparation SPMC/bisacodyl group and a conventional split PEG group. We compared preparation adequacy using the Boston bowel preparation scale (BBPS), ease of use using a modified Likert scale (LS), compliance/satisfaction level using a visual analogue scale (VAS), and safety by monitoring adverse events during the colonoscopy between the two groups.

Results

A total of 365 patients were evaluated by intention to treat (ITT) analysis, and 319 were evaluated by per protocol (PP) population analysis (153 for SPMC/bisacodyl, 166 for PEG). The mean total BBPS score was not different between the two groups in both the ITT and PP analyses (p>0.05). The mean VAS score for satisfaction and LS score for the ease of use were higher in the SPMC/bisacodyl group (p<0.001). The adverse event rate was lower in the SPMC/bisacodyl group than in the PEG group (p<0.05).

Conclusions

The SPMC/bisacodyl treatment was comparable to conventional PEG with respect to bowel preparation adequacy and superior with respect to compliance, satisfaction, and safety.

Systematic review and meta-analysis: sodium picosulfate/magnesium citrate vs. polyethylene glycol for colonoscopy preparation

BACKGROUND AND AIMS

Previous studies comparing sodium picosulfate/magnesium citrate (SPMC) with polyethylene glycol (PEG) drew inconsistent conclusions. We conducted a meta-analysis to compare the performance of the two agents for colonoscopy preparation.

METHODS

A search of randomized controlled trials (RCTs) up to July 2015 was acquired, using MEDLINE, EMBASE, the Cochrane Library, and Google Scholar. We calculated the pooled estimates of bowel cleanliness, polyp/adenoma detection rate (PDR/ADR), completion of preparation, willingness to repeat identical bowel preparation, and adverse events by using relative risk (RR) with random-effects models. A non-inferiority analysis was performed, comparing SPMC to PEG for bowel cleaning efficacy.

RESULTS

A total of 25 RCTs were qualified for analysis. There was no statistically significant difference between the two agents in bowel cleanliness, but the effect direction showed a trend in favor of PEG (RR 0.93; 95 % CI 0.86-1.01, P = 0.07). The non-inferiority analysis demonstrated the non-inferiority of SPMC by retaining at least 90 % of the effect of PEG. Similarly, there was no significant difference between the two agents in PDR (RR 0.94; 95 % CI 0.82-1.08, P = 0.37) and ADR (RR 0.88; 95 % CI 0.74-1.05, P = 0.16). However, a higher proportion of patients were likely to complete SPMC preparation (RR 1.08; 95 % CI 1.04-1.13, P < 0.001) and were willing to repeat SPMC preparation (RR 1.44; 95 % CI 1.25-1.67, P < 0.001). The total number of adverse events was significantly lower in the SPMC group (RR 0.78; 95 % CI 0.66-0.93, P = 0.004).

CONCLUSIONS

SPMC, with better tolerability and less frequent adverse events, demonstrated non-inferior bowel cleaning efficacy than that of the PEG. Large-scale, well-organized, head-to-head studies are warranted.

Polyethylene glycol versus sodium picosulfalte bowel preparation in the setting of a colorectal cancer screening program

BACKGROUND

Adequate bowel preparation for colonoscopy is an important predictor of colonoscopy quality.

OBJECTIVE

To determine the difference in terms of effectiveness between different existing colon cleansing products in the setting of a colorectal cancer screening program.

METHODS

The records of consecutive patients who underwent colonoscopy at the Montreal General Hospital (Montreal, Quebec) between April 2013 and April 2014 were retrospectively extracted from a dedicated electronic digestive endoscopic institutional database.

RESULTS

Overall, 2867 charts of patients undergoing colonoscopy were assessed, of which 1130 colonoscopies were performed in a screening setting; patients had adequate bowel preparation in 90%. Quality of preparation was documented in only 61%. Bowel preparation was worse in patients receiving sodium picosulfate (PICO) alone compared with polyethylene glycol, in a screening setting (OR 0.3 [95% CI 0.2 to 0.6]). Regardless of the preparation type, the odds of achieving adequate quality cleansing was 6.6 for patients receiving a split-dose regimen (OR 6.6 [95% CI 2.1 to 21.1]). In multivariable analyses, clinical variables associated with inadequate bowel preparation in combined population were use of PICO, a nonsplit regimen and inpatient status. The polyp detection rate was very high (45.6%) and was correlated with withdrawal time.

CONCLUSION

Preparation quality needs to be more consistently included in the colonoscopy report. Split-dose regimens increased the quality of colon cleansing across all types of preparations and should be the preferred method of administration. Polyethylene glycol alone provided better bowel cleansing efficacy than PICO in a screening setting but PICO remains an alternative in association with an adjuvant.

Randomized controlled trial of low-volume bowel preparation agents for colonic bowel preparation: 2-L polyethylene glycol with ascorbic acid versus sodium picosulfate with magnesium citrate

PURPOSE

Both 2-L polyethylene glycol with ascorbic acid (2-L PEG/Asc) and sodium picosulfate with magnesium citrate (SP/MC) are low-volume combined agents for colonic preparation. The aim of the current study was to compare the preparation adequacy and patient tolerability of 2-L PEG/Asc and SP/MC.

METHODS

We performed a prospective randomized controlled study in outpatients undergoing daytime colonoscopy at a tertiary academic hospital. We compared preparation adequacy based on the Boston Bowel Preparation Scale (BBPS), polyp and adenoma detection rate (PDR and ADR), compliance, tolerability for ease and palatability, intention to reuse, and patient satisfaction using a questionnaire between 2-L PEG/Asc and three sachets of SP/MC, both given in a split-dose method.

RESULTS

A total of 388 patients were evaluated based on intention to treat (ITT) and 356 patients per protocol (PP). No significant differences in preparation adequacy were observed in ITT and PP analyses, based on the BBPS (p > 0.05). The PDR and ADR were greater than 60 and 40% in both groups, respectively (p > 0.05). Compliance levels were higher in the 2-L PEG/Asc group than in the SP/MC group (p < 0.001). Satisfaction (ITT, p = 0.014; PP, p = 0.032) and palatability (ITT and PP, p < 0.001) levels were higher in the SP/MC group than in the 2-L PEG/Asc group, but values for tolerability for ease and intention to reuse were similar in both groups (ITT and PP, p > 0.05).

CONCLUSIONS

Both 2-L PEG/Asc and SP/MC had adequate bowel cleansing efficacy to satisfy PDR and ADR as quality indicator and had showed similar tolerability.

'Pico-Bello-Klean study': effectiveness and patient tolerability of bowel preparation agents sodium picosulphate-magnesium citrate and polyethylene glycol before colonoscopy. A single-blinded randomized trial

OBJECTIVES

Adequate bowel preparation is an important step for an effective colonoscopy. Polyethylene glycol solution (Kleanprep) and sodium picosulphate with a magnesium citrate solution (Picoprep) are bowel cleansing agents registered and available for this purpose. So far, the results of studies comparing the effectiveness of bowel cleansing between the two agents are inconclusive. This may be because of differences in administration regimes and subjective measurement of bowel cleansing.In this single-blinded randomized-controlled trial, the effectiveness of Kleanprep and Picoprep was examined using a split-dose regimen and an objective bowel cleansing score system.

PATIENTS AND METHODS

One hundred and seventy-three consecutive patients referred for outpatient colonoscopy were included, the required number based on power analysis. Eighty-eight patients received Kleanprep; 85 received Picoprep. The primary outcome was the effectiveness of bowel cleansing using the Boston Bowel Preparation Score. The secondary outcome was patient tolerability measured using a questionnaire. An intention-to-treat-analysis was carried out.

RESULTS

The overall Boston Bowel Preparation Score between Kleanprep and Picoprep was not significantly different (P=0.182). On reviewing segment scores, there were also no significant differences between Kleanprep and Picoprep. Patients using Picoprep scored significantly better on the aspects of convenience and flavour of the preparation agent compared with patients using Kleanprep (P<0.001). Side effects such as nausea (P=0.011), vomiting (P=0.001), headache (P=0.003) and bloating (P<0.001) were experienced less significantly by patients using Picoprep.

CONCLUSION

The present study did not find a difference in the effectiveness of bowel cleansing between Kleanprep and Picoprep. Both were found to be adequate cleansing agents. Picoprep was significantly better tolerated than Kleanprep. Therefore, we recommend Picoprep as a first-choice regimen for bowel preparation before colonoscopy.

Meta-analysis: the relative efficacy of oral bowel preparations for colonoscopy 1985-2010

BACKGROUND

Previous reviews of bowel preparation for colonoscopy have given contradictory answers.

AIM

To provide a definitive insight, using PRISMA-compliant methodology.

METHODS

A comprehensive literature review identified randomised controlled trials comparing bowel preparation regimens. Data for quality of bowel preparation were pooled in multiple meta-analyses exploring a range of inclusion criteria.

RESULTS

A total of 104 qualifying studies were identified, the majority of which involved comparisons of sodium phosphate (NaP) or polyethylene glycol (PEG). There was no significant difference demonstrated between NaP and PEG overall (OR = 0.82; 95% CI = 0.56-1.21; P = 0.36). Cumulative meta-analysis demonstrated that this conclusion has been qualitatively similar since the mid 1990s, with little quantitative change for the past 10 years. Amongst studies with previous day dosing in both study arms there was a significant advantage in favour of PEG (OR = 1.78; 95% CI = 1.13-2.81; P = 0.006). Studies focussing on results in the proximal colon also favoured PEG (OR = 2.36; 95% CI = 1.16-4.77; P = 0.012). PEG was also significantly more effective than non-NaP bowel preparation regimens (OR = 2.02; 95% CI = 1.08-3.78; P = 0.03). Other comparisons showed no significant difference between regimens.

CONCLUSIONS

Although there is no compelling evidence favouring either of the two most commonly used bowel preparation regimens, this may reflect shortcomings in study design. Where studies have ensured comparable dosage, or the clinically relevant outcome of proximal bowel clearance is considered, PEG-based regimens offer the most effective option.

A multicentre, observational study of sodium picosulfate and magnesium citrate as a precolonoscopy bowel preparation

BACKGROUND

Sodium picosulfate with magnesium citrate (PSMC) has been available as a precolonoscopy bowel preparation in Canada since 2005. A high patient acceptability and preference appears to have contributed to its wide adoption across the country. Despite its frequent use, there are relatively few published studies of this product, especially reports regarding its use in routine clinical practice. Moreover, to date, there have been no Canadian studies of any kind.

OBJECTIVE

To conduct a preliminary evaluation of PSMC by prospectively collecting data describing its effectiveness.

METHODS

In the present multicentre, observational study, sequential patients used PSMC according to each institution's standard colonoscopy protocol. Differences in bowel cleansing protocols included dose timing, fluid intake, dietary restrictions and administration of bisacodyl. During colonoscopy, preparation quality was rated separately for the right and left sides of the colon.

RESULTS

Of the 613 patients entered, 606 were evaluable for efficacy. For the right and left colon, respectively, 93.0% and 96.2% of preparations were rated either 'excellent' or 'adequate'. In the 334 patients who received adjunctive bisacodyl and the 272 patients who did not, the results were similar: for the right and left colon, 92.3% and 97.1% of those who did not, and 93.4% and 95.7% of those who did receive bisacodyl, respectively, were rated either 'excellent' or 'adequate'.

CONCLUSIONS

Despite the differences in bowel cleansing protocols used at each hospital (including an additional laxative), PSMC consistently yielded a high percentage of positive ratings for efficacy.

Randomized clinical trial comparing sodium picosulfate with mannitol on the preparation FOR colonoscopy in hospitalized patients

BACKGROUND: The cleansing of the colon for a colonoscopy exam must be complete so as to allow the visualization and inspection of the intestinal lumen. The ideal cleansing agent should be easily administered, have a low cost, and minimum collateral effects. Sodium picosulfate together with the magnesium citrate is a cathartic stimulant and mannitol is an osmotic laxative, both usually used for this purpose. AIMS: Assess the colon cleanliness comparing the use of mannitol and sodium picosulfate as well as evaluate the level of patient satisfaction, the presence of foam, pain, and abdominal distension in hospitalized patients undergoing colonoscopy. METHODS: A prospective, randomized, single-blind study with 80 patients that compared two groups: mannitol (40) and sodium picosulfate (40). Both groups received the same dietary orientation. The study was approved by the hospital’s Ethics and Research Committee. The endoscopist was blind to the type of preparation. Outcomes evaluated: level of the colon’s cleanliness, patient’s satisfaction, the presence of foam, abdominal pain and distension, and the duration of the exam. The data was analyzed by means of the chi-squared test for proportions and Mann-Whitney for independent samples. RESULTS: There were no statistically significant differences between the groups in relation to the level of the colon’s cleanliness, patient’s satisfaction, the presence of foam, abdominal pain, and the duration of the exam. Fifteen percent of the exams of the mannitol group were interrupted while from the sodium picosulfate group it was 5%. The presence of foam was similar for both groups. The average duration for carrying out the exam was 28.44 minutes for the mannitol group and 35.59 minutes for the sodium picosulfate group. Abdominal distension was more frequent in the mannitol group. If they would have to do the same exam, the answer was that 80% said yes from the mannitol group and 92.5% from the sodium picosulfate group. CONCLUSION: The quality of the colon preparation, foam formation, exam duration, and the collateral effects (nauseas, vomiting, and abdominal pain) were similar in both kinds of preparations. Abdominal distension was greater in the mannitol group. Both methods of preparation were well accepted by the hospitalized patients.

Randomised, placebo-controlled, double-blind study to investigate the efficacy and safety of the acute use of sodium picosulphate in patients with chronic constipation

There are few studies supporting the effective and safe use of laxatives for constipation. This study examined the short-term efficacy and safety of sodium picosulphate in patients with chronic constipation. Patients with a history of chronic constipation for at least 3 months were randomised to receive 7 mg sodium picosulphate or placebo for three consecutive nights. Patients recorded stool frequency and consistency, straining, bloating, and pain at baseline and during treatment. Vital signs, haematocrit, serum creatinine and electrolytes were monitored. Primary end-point for efficacy was the occurrence of a response to treatment, defined as improvement in stool frequency and occurrence of straining. All 57 randomised patients (sodium picosulphate n = 29, placebo n = 28; mean age 54.8 and 54.1 years) completed the study. Sodium picosulphate produced a treatment response (improved stool frequency and straining) in 82.8% compared with 50% in the placebo group (p = 0.010) and reduced bloating more often than placebo. There were no serious adverse events and one patient with diarrhoea and another with abdominal pain in each treatment group. There were no cardiovascular effects, changes in serum haematocrit, creatinine or electrolytes in either group. This study confirmed that sodium picosulphate is an effective, well-tolerated and safe laxative in the acute treatment of constipation.

Systematic review: oral bowel preparation for colonoscopy

BACKGROUND

There are many published trials of colon cleansing regimens for colonoscopy but no clear consensus regarding relative performance.

AIM

To identify high quality controlled trials comparing two or more bowel preparation regimens and to compare efficacy and tolerability.

METHODS

A comprehensive systematic review was carried out to identify candidate studies. Quality appraisal was carried out on all identified studies. Results were meta-analysed where possible and qualitatively compared if not.

RESULTS

Eighty-two studies qualified for analysis. Polyethylene glycol and sodium phosphate were the most frequently investigated preparations. There was no significant efficacy difference between the two, but sodium phosphate was better tolerated. Sodium picosulphate/magnesium citrate, a commonly prescribed preparation, was investigated in four studies, with no clear benefit over other regimens demonstrated. Safety was not recognized as a problem in the randomized controlled trials. Published case series demonstrate that sodium phosphate is associated with the highest risk of clinically significant electrolyte disturbances.

CONCLUSION

Shortcomings in study design limit the value of many of the studies. Based on these results, no single bowel preparation emerges as consistently superior. New preparations are required that combine better efficacy and tolerability, in addition to rigorous new validated study designs, allowing unequivocal comparisons to be made.

Commonly used preparations for colonoscopy: efficacy, tolerability, and safety--a Canadian Association of Gastroenterology position paper

INTRODUCTION

The increased demand for colonoscopy, coupled with the introduction of new bowel cleansing preparations and recent caution advisories in Canada, has prompted a review of bowel preparations by the Canadian Association of Gastroenterology.

METHODS

The present review was conducted by the Clinical Affairs group of committees including the endoscopy, hepatobiliary/transplant, liaison, pediatrics, practice affairs and regional representation committees, along with the assistance of Canadian experts in the field. An effort was made to systematically assess randomized prospective trials evaluating commonly used bowel cleansing preparations in Canada.

RESULTS

Polyethylene glycol (PEG)-; sodium phosphate (NaP)-; magnesium citrate (Mg-citrate)-; and sodium picosulphate, citric acid and magnesium oxide (PSMC)-containing preparations were reviewed. Regimens of PEG 2 L with bisacodyl (10 mg to 20 mg) or Mg-citrate (296 mL) are as effective as standard PEG 4 L regimens, but are better tolerated. NaP preparations appear more effective and better tolerated than standard PEG solutions. PSMC has good efficacy and tolerability but head-to-head trials with NaP solutions remain few, and conclusions equivocal. Adequate hydration during preparation and up to the time of colonoscopy is critical in minimizing side effects and improving bowel cleansing in patients receiving NaP and PSMC preparations. All preparations may cause adverse events, including rare, serious outcomes. NaP should not be used in patients with cardiac or renal dysfunction (PEG solution is preferable in these patients), bowel obstruction or ascites, and caution should be exercised when used in patients with pre-existing electrolyte disturbances, those taking medications that may affect electrolyte levels and elderly or debilitated patients. Health Canada's recommended NaP dosing for most patients is two 45 mL doses 24 h apart. However, both safety and efficacy data on this dosing schedule are lacking. Many members of the Canadian Association of Gastroenterology expert panel administer both doses within 24 h, as studied in clinical trials, after careful one-on-one discussion of risks and benefits in carefully selected patients. Safety data on PSMC and combination preparations in North America are limited and clinicians are encouraged to keep abreast of developments in this area.

CONCLUSIONS

All four preparations reviewed provided effective bowel cleansing for colonoscopy in the majority of patients, with varying tolerability. Adequate hydration is essential in patients receiving the preparations.

A randomized prospective trial comparing different regimens of oral sodium phosphate and polyethylene glycol-based lavage solution in the preparation of patients for colonoscopy

BACKGROUND

Regulatory agencies have warned clinicians regarding the risk of electrolyte abnormalities if more than two 45-mL bottles of oral sodium phosphate (NaP) solution are administered within a 24-hour period.

OBJECTIVE

To compare the efficacy, safety, and tolerability of different regimens of oral NaP and polyethylene glycol (PEG).

DESIGN

Randomized controlled trial.

SETTING

Teaching hospital outpatient endoscopy clinic.

PATIENTS

Two hundred outpatients without comorbidities who underwent routine colonoscopy.

INTERVENTIONS

Two bottles of NaP, 6, 12, or 24 hours apart; or 4 L PEG.

MAIN OUTCOME MEASUREMENTS

Bowel preparation quality, patient tolerability, and electrolyte changes.

RESULTS

The 12- and 24-hour NaP achieved better cleansing than the 6-hour NaP or PEG. Only 8.5% and 8.3% of patients in the 24- and 12-hour NaP had poor preparations, respectively, compared with 15.6% and 23.4% in the 6-hour NaP and PEG, respectively. The poorer preparation scores with PEG were partly because of a greater amount of colonic fluid. There were no relevant electrolyte changes with PEG, whereas hypokalemia, hypocalcemia, or hyperphosphatemia developed in 5% to 57% of patients on NaP. All regimens were poorly tolerated by patients.

LIMITATIONS

The study was likely underpowered to detect small group differences in electrolytes.

CONCLUSIONS

A 24- or 12-hour NaP bowel preparation strategy was more effective than NaP 6 hours apart or PEG. PEG use is associated with more residual colonic fluid but represents an alternative to NaP in some clinical situations.

Which is the optimal bowel preparation for colonoscopy - a meta-analysis

OBJECTIVE

To assess which bowel preparation agent is most effective.

METHODS

A search of randomized trials between January 1990 and July 2005 was obtained, using MEDLINE and PubMed databases, and the Cochrane Central Register of Controlled Trials. Meta-analysis was performed using the Forest plot review.

RESULTS

Sodium phosphate (NaP) was more effective in bowel cleansing than polyethylene glycol (PEG) - odds ratio 0.75 (95%CI: 0.65-0.88; P = 0.0004); and sodium picosulphate (SPS) - odds ratio 0.52 (95%CI: 0.34-0.81; P = 0.004). PEG and SPS were comparable in bowel cleansing ability, odds ratio 1.69 (95%CI: 0.92-3.13; P = 0.09). NaP was more easily completed by patients compared to PEG, odds ratio 0.16 (95%CI: 0.09-0.29; P < 0.00001). More patients were able to complete SPS than PEG, but this was not statistically significant - odds ratio 0.56 (95%CI: 0.28-1.13; P = 0.11). NaP and PEG were comparable in terms of adverse events, odds ratio 0.98 (95%CI: 0.82-1.17; P = 0.81), although NaP resulted in more asymptomatic hypokalaemia and hyperphosphataemia. NaP and SPS appeared to have similar incidence of adverse events. PEG resulted in more adverse events than SPS, odds ratio 3.82 (95%CI: 1.60-9.15; P = 0.003).

CONCLUSIONS

NaP was more effective in bowel cleansing than PEG or SPS and was comparable in terms of adverse events. Patients have more difficulty completing PEG than NaP and SPS. Biochemical changes associated with a small-volume preparation like NaP, albeit largely asymptomatic, mandate caution in patients with cardiovascular or renal impairment.

Audit of bowel preparation with Picolax (sodium picosulfate plus magnesium citrate) for colonoscopy

The aim of this study was to assess the quality of bowel preparation for colonoscopy with standard dose Picolax (two sachets administered on the day prior to the procedure, as per the manufacturer's instructions) in a large cohort of patients. A retrospective audit was performed of colonoscopies performed at our institution over a 1-year period. Patients were excluded if standard dose Picolax was not used, if the quality of the bowel preparation was not recorded or if completion of the procedure was not recorded. Of the 619 fully evaluable cases, the quality of the bowel preparation was assessed by the colonoscopist performing the procedure as good in 263 (42.5%), satisfactory in 242 (39.1%) and poor in 114 (18.4%) of the cases. In only 28 (4.5%) cases, poor bowel preparation was the reason cited for an incomplete colonoscopy. There was no difference in the quality of bowel preparation between inpatients and outpatients. In clinical practice, Picolax is an effective bowel preparation for colonoscopy in the vast majority of cases.

Management of constipation in palliative care patients undergoing opioid therapy: is polyethylene glycol an option?

This study assessed the efficacy of laxative use for treatment of constipation in patients receiving opioid therapy, with special attention to polyethylene glycol 3350/electrolyte solution (PEG-ES). Computerized data from 206 patients were analyzed using descriptive statistics. Subgroups were analyzed using confirmatory statistics. Constipation occurred in 42.7 percent of patients. Laxatives were administered to 74.3 percent of these patients using a standardized step scheme, with good results in 78.4 percent. As a therapy for constipation, the combined administration of PEG-ES, sodium picosulphate, and liquid paraffin proved most effective, although statistical analysis yielded no significance. Early use of PEG-ES using a step scheme holds promise for treatment of opioid-related constipation in palliative care patients, although further investigation is warranted.

Single blind, randomised trial of efficacy and acceptability of oral picolax versus self administered phosphate enema in bowel preparation for flexible sigmoidoscopy screening

OBJECTIVE

To compare the acceptability and efficacy of two methods of self administered bowel preparation for flexible sigmoidoscopy screening: a single phosphate enema and a single sachet of Picolax.

DESIGN

Single blind, randomised trial.

SETTING

Endoscopy units of two general hospitals.

PARTICIPANTS

1442 men and women aged 55-64 years who had agreed to be screened by flexible sigmoidoscopy. MAIN OUTCOME MESURESs: Attendance rates, compliance with allocated preparations, adverse effects, quality of bowel preparation, procedure time, and yield of neoplasia.

RESULTS

Compliance with the enema was higher than with the Picolax (608 (84%) v 566 (79%); difference 6%, 95% confidence interval 2% to 10%). Almost half of those who refused Picolax used an enema at home. Wind, incontinence, and sleep disturbance were more frequent in the Picolax group than the enema group; bottom soreness was more frequent in the enema group. Around 30% (187) found the diet restriction required by Picolax difficult; 78% (471) found the enema easy to administer. The quality of preparation was better with the enema; the proportion of procedures complete to the descending colon was greater and the mean duration of the procedure was shorter. There was no significant difference in polyp detection rates.

CONCLUSION

A single phosphate enema self administered around one hour before leaving home is a more acceptable and effective method of preparing the distal bowel for flexible sigmoidoscopy than Picolax.

Comparison of two bowel preparations for colonoscopy: sodium picosulphate with magnesium citrate versus sulphate-free polyethylene glycol lavage solution

OBJECTIVES

Adequate preparation of the bowel is essential for accurate colonoscopic examination. We compared colonic preparation with sodium picosulphate plus magnesium citrate (SPS-Mg) with sulphate-free polyethylene glycol electrolyte lavage (PEG-EL) solution before colonoscopy, for quality of bowel cleansing, patient discomfort, and side effects.

METHODS

Sixty-eight consecutive patients were randomly assigned to receive either 3 sachets of SPS-Mg (16.5 g each) (n = 39) or 3 L of PEG-EL (n = 29) on the day before colonoscopy. Shortly before the procedure each patient was interviewed to determine the degree of discomfort (1 = none or mild, 2 = moderate, 3 = severe) and side effects. The quality of bowel cleansing was graded by a gastroenterologist who was unaware of the method of preparation (from 1 = poor to 4 = excellent).

RESULTS

Of the 29 PEG-EL patients, four (14%) did not complete the preparation because of side effects. The degree of discomfort was significantly greater with PEG-EL (mean score, 2.3 +/- 0.7) than with SPS-Mg (mean score, 1.4 +/- 0.5; p < 0.01). Nausea and vomiting were significantly more common in the PEG-EL group (38% vs 13%; p < 0.05). Using intention-to-treat analysis, bowel cleansing proved to be significantly better with SPS-Mg than with PEG-EL (mean score +/- SD, 3.05 +/- 0.9 and 2.57 +/- 1.0, respectively; p = 0.036).

CONCLUSIONS

Colonic preparation with SPS-Mg is better tolerated, associated with significantly fewer side effects, and results in higher quality bowel cleansing than preparation with PEG-EL.

Barium enema preparation: a study of low-residue diet, "Picolax' and 'Kleen-Prep'

A prospective, randomized three-arm trial is presented of 150 consecutive patients attending for double-contrast barium enema (BE). This compares 'Picolax' (a combined stimulant and osmotic agent), 'Picolax' following a 3 day low-residue diet and 'Kleen-Prep' (a polyethylene-glycol osmotic agent). Faecal clearance, mucosal coating and colon fluid were scored in four colonic segments by two radiologists working independently and blinded to the preparation used. Analyses of an elderly subgroup and of side effects was performed. Low-residue diet conferred no benefit to Picolax preparation, which was satisfactory (ability to exclude 5 mm polyps) in 80% of patients. Kleen-Prep failed to achieve adequate preparation in 46%, due to excess fluid and poor mucosal coating. Kleen-Prep caused more patient nausea, abdominal bloating and pain than Picolax. Patients 70 years and older had similar results. Low-residue diet need not be used in addition to Picolax. Kleen-Prep as a single agent is not recommended for BE preparation.

Bowel preparation for colonoscopy: a randomized prospective trail comparing sodium phosphate and polyethylene glycol in a predominantly elderly population

Many patients find polyethylene glycol-based preparations (PEG) difficult to take because of the large volume of fluid they are required to consume. One hundred and sixteen predominantly elderly patients were randomized to receive either sodium phosphate (n = 61) or PEG (n = 55) bowel preparations before colonoscopy. Patients with a history of symptomatic ischaemic heart disease or cerebrovascular disease in the preceding 6 months, severe liver disease or heart failure, or serum creatinine above 200 micrograms/L were excluded from the study. Each patient filled in a questionnaire about the bowel preparation prior to the procedure. The colonoscopists, who were not aware which preparation had been used, were asked to complete a questionnaire about the quality of the bowel preparation after the procedure. The patients found the sodium phosphate preparation slightly more tolerable than PEG. Side effects were slightly more common with sodium phosphate. Neither difference was statistically significant. However, 91% of patients who had previously had PEG found sodium phosphate easier to take. Approximately 25% of patients in each group experienced at least one episode of incontinence. The colonoscopists found no difference in the overall quality of the bowel preparation. The amount of fluid in the colon was greater in patients prepared with PEG. As expected, patients taking sodium phosphate developed hyperphosphataemia (mean phosphate level before colonoscopy 1.56 mmol/L, normal 0.8 -1.3). They also had a lower mean serum potassium level (3.8 mmol/L) than the PEG group (4.2 mmol/L). However, there were no clinically significant consequences. Sodium phosphate was a safe and effective bowel preparation for colonoscopy in this carefully selected group of patients. It was preferred by patients who had previously had PEG. Many elderly patients were found to develop faecal incontinence, irrespective of the type of bowel preparation used.

The quest for a more acceptable bowel preparation: comparison of a polyethylene glycol/electrolyte solution and a mannitol/Picolax mixture for colonoscopy

Eighty-nine consecutive patients attending for day-case colonoscopy were randomly allocated either polyethylene glycol/balanced electrolyte (PEG) mixture (n = 45) or a mannitol/Picolax mixture (n = 44). Both preparations were administered in two fractions. Patients recorded their experience of the preparation on a questionnaire and one of two experienced endoscopists (unaware of the type of preparation given) assessed the result of bowel cleansing. Carbon dioxide insufflation was used for all examinations. Good/excellent bowel cleansing occurred in significantly more patients given PEG, 43 (96%), than those allocated mannitol/Picolax, 34 (77%), p = 0.01. More patients receiving mannitol/Picolax were able to complete the preparation in full than patients receiving PEG (38 vs 27, p = 0.01). More patients found the taste of mannitol/Picolax pleasant compared to PEG (46% vs 20%). Both preparations had a similar side-effect profile. Of those patients tested, 13% receiving mannitol/Picolax had a postural drop in blood pressure and blood parameters suggestive of mild dehydration. A fractionated administration of PEG as a bowel preparation for day-case colonoscopy is well tolerated and superior as a cleansing agent to a mannitol/Picolax combination. Provided carbon dioxide is used as the insufflating agent, mannitol/Picolax is an acceptable alternative in fit, young patients intolerant of PEG.