Low-volume morning-only polyethylene glycol with specially designed test meals versus standard-volume split-dose polyethylene glycol with standard diet for colonoscopy: a prospective, randomized trial

Adherence and Effectiveness of MoviPrepⓇ in Bowel Preparation for Colonoscopy: A Multicenter Study from the Hiroshima GI Endoscopy Research Group

Objectives

Bowel preparation is burdensome because of long cleansing times and large dose volumes of conventional polyethylene glycol (PEG) lavage solution NiflecⓇ (Nif). MoviPrep (Mov)Ⓡ is a hyperosmolar preparation of PEG, electrolytes, and ascorbic acid; despite the smaller dose volume of 2 L, it can be challenging for many patients. We examined a more effective and acceptable bowel preparation method without compromising cleanliness and effectiveness, combining low-residue diet and laxative (Modified Brown Method) in Mov administered 1 day pre-colonoscopy.

Methods

This multicenter, randomized, open-label, parallel-group comparative study, conducted at Hiroshima University Hospital and 7 affiliated hospitals in May 2015-March 2016, evaluated adherence to and effectiveness of Mov in bowel preparation. Participants (n=380) were allocated to receive 1 of 3 pre-colonoscopy regimens: Nif+Modified Brown Method (Group A), Mov+Modified Brown Method (Group B), or Mov+Laxative (Group C).

Results

Total intake volume showed no significant difference among the groups. Bowel preparation time was significantly shorter in Group B (112.4±44.8 min, n=118) than in Groups A (131.3±59 min, n=105) and C (122.6±48.1 min, n=115). Sleep disturbance (37%) was significantly higher in Group B than Group A; distension (11%) was significantly lower in Group C than in Groups A and B (p<0.05, respectively). No severe adverse events occurred in any group.

Conclusions

Mov+Modified Brown method provided significantly shorter bowel preparation time, with no significant difference in total intake volume among the regimens. Mov+Laxative yielded significantly less distension than the other groups, with bowel preparation equivalent to that of the Nif+Modified Brown method.

Same-day single-dose vs large-volume split-dose regimens of polyethylene glycol for bowel preparation: A systematic review and meta-analysis

BACKGROUND

Split-dose regimens (SpDs) of 4 L of polyethylene glycol (PEG) have been established as the “gold standard” for bowel preparation; however, its use is limited by the large volumes of fluids required and sleep disturbance associated with night doses. Meanwhile, the same-day single-dose regimens (SSDs) of PEG has been recommended as an alternative; however, its superiority compared to other regimens is a matter of debate.

AIM

To compare the efficacy and tolerability between SSDs and large-volume SpDs PEG for bowel preparation.

METHODS

We searched MEDLINE/PubMed, the Cochrane Library, RCA, EMBASE and Science Citation Index Expanded for randomized trials comparing (2 L/4 L) SSDs to large-volume (4 L/3 L) SpDs PEG-based regimens, regardless of adjuvant laxative use. The pooled analysis of relative risk ratio and mean difference was calculated for bowel cleanliness, sleep disturbance, willingness to repeat the procedure using the same preparation and adverse effects. A random effects model or fixed-effects model was chosen based on heterogeneity analysis among studies.

RESULTS

A total of 18 studies were included. There was no statistically significant difference of adequate bowel preparation (relative risk = 0.97; 95%CI: 0.92-1.02) (14 trials), right colon Boston Bowel Preparation Scale (mean difference = 0.00; 95%CI: -0.04, 0.03) (9 trials) and right colon Ottawa Bowel Preparation Scale (mean difference = 0.04; 95%CI: -0.27, 0.34) (5 trials) between (2 L/4 L) SSDs and large-volume (4 L/3 L) SpDs, regardless of adjuvant laxative use. The pooled analysis favored the use of SSDs with less sleep disturbance (relative risk = 0.52; 95%CI: 0.40, 0.68) and lower incidence of abdominal pain (relative risk = 0.75; 95%CI: 0.62, 0.90). During subgroup analysis, patients that received low-volume (2 L) SSDs showed more willingness to repeat the procedure using the same preparation than SpDs (P < 0.05). No significant difference in adverse effects, including nausea, vomiting and bloating, was found between the two arms (P > 0.05).

CONCLUSION

Regardless of adjuvant laxative use, the (2 L/4 L) SSD PEG-based arm was considered equal or better than the large-volume (≥ 3 L) SpDs PEG regimen in terms of bowel cleanliness and tolerability. Patients that received low-volume (2 L) SSDs showed more willingness to repeat the procedure using the same preparation due to the low-volume fluid requirement and less sleep disturbance.

Effectiveness of low-volume split-dose versus same-day morning polyethylene glycol regimen for adequacy of bowel preparation in patients undergoing colonoscopy: A single-blinded randomized controlled trial

BACKGROUND

Successful completion of colonoscopy depends largely on the quality of bowel preparation. Polyethylene glycol (PEG) is a commonly used preparation for colonoscopy. The timing of bowel preparation has evolved from previous day evening to the currently recommended split-dose regimen. It was observed that consumption of entire or a portion of PEG on the previous day can interfere with work and sleep. Hence, we designed this single-blinded randomized controlled trial (RCT) to evaluate the efficacy, tolerability, and acceptability of the same-day PEG as compared with lowvolume split-dose PEG in patients undergoing late morning colonoscopy.

METHODS

A total of 384 patients were randomized to same-day (SD group; n = 192) and split-dose (SPL group; n = 192) bowel preparation. The patients in both the groups received bisacodyl 10 mg at bedtime on the day prior to colonoscopy. The patients in the SD group took 2 L of PEG between 5:00 AM and 7:00 AM on the day of colonoscopy. The SPL group took 1 L of PEG between 6:00 PM and 7:00 PM on the preceding day and another liter between 6:00 AM and 7:00 AM on the day of colonoscopy. The adequacy of bowel preparation was assessed using the Boston Bowel Preparation Scale (BBPS). Tolerability was scored by recording symptoms such as nausea, vomiting, bloating, and abdominal pain. Acceptability was based on the overall satisfaction, willingness to repeat the same preparation, and interference with sleep on the preceding night.

RESULTS

The median (interquartile range, [IQR]) BBPS in the SD group was 8 (6-9) while that in the SPL group was 6 (5-8) and this difference was statistically significant (p < 0.001). Similarly, a significantly higher proportion of patients in the SD group (86%) achieved adequate bowel preparation (BBPS score ≥ 6) when compared to those in the SPL group (73.4%) (p = 0.002). Tolerability as assessed by nausea, vomiting, bloating, and abdominal pain was similar in both the groups. There was also no significant difference with respect to overall satisfaction of taking bowel preparation (p = 0.33) or willingness to repeat the same regimen (p = 0.37) between the two groups. Patients in the SPL group had more interference with sleep on the preceding night (54% vs. 14.5%, p < 0.001).

CONCLUSION

Same-day morning PEG regimen can be considered an effective, well-tolerated, and acceptable bowel preparation for colonoscopy.

Impact of Prepackaged Low-Residue Diet on Bowel Preparation for Colonoscopy: A Meta-analysis

This meta-analysis aimed to evaluate the impact of prepackaged low-residue diet (PLRD) on bowel preparation for colonoscopy. We searched PubMed, Web of Science, EMBASE, and Cochrane Library databases from inception to August 2020. Randomized controlled trials (RCTs) comparing PLRD with clear liquid diet (CLD) or self-prepared LRD were considered for inclusion. The analysis calculated the odds ratio (OR) for the rate of adequate bowel preparation, patient tolerance, willingness to repeat bowel preparation, tolerability of bowel preparation, and overall adverse effects. Five RCTs published between 2006 and 2019 (N = 561) were included in our meta-analysis. Compared with the traditional CLD or self-prepared LRD, PLRD showed significantly higher rates of adequate bowel preparation (OR, 2.16; 95% confidence interval [CI], 1.18-3.98; p = .01), patient tolerance (OR, 1.99; 95% CI, 1.30-3.07; p = .002), and willingness to repeat the bowel preparation (OR, 1.68; 95% CI, 1.05-2.70; p = .03), with no differences in adverse events (OR, 0.93; 95% CI, 0.59-1.46; p = .75). Prepackaged low-residue diet improved bowel preparation quality, patient tolerance, and willingness to repeat bowel preparations. Importantly, PLRD does not increase the incidence of adverse events. This suggests that it is effective and safe to use PLRD for bowel preparation before colonoscopy.

Split-dose vs same-day bowel preparation for afternoon colonoscopies: A meta-analysis of randomized controlled trials

BACKGROUND

Quality of bowel preparation in afternoon colonoscopies has been a struggle. Currently, a choice of same-day preparation (SaD) or split-dose preparation (SpD) exists; however, randomized controlled trials’ results have varied. 

AIM

To examine the outcomes of SaD and SpD for afternoon colonoscopies.

METHODS

An extensive literature search was conducted using multiple databases. Only randomized controlled trials (RCTs) in adults that compared SaD to SpD with Ottawa bowel preparation score (OBPS) were included. Odds ratio (OR) or mean difference was used to analyze outcomes.

RESULTS

Eleven RCTs were included (n = 1846). No difference was observed for satisfactory bowel preparation based on OBPS among participants receiving SaD vs SpD (OR 0.77; 95%CI: -0.57-1.03; P = 0.07; I² = 5%). Subgroup analysis showed no difference in terms of satisfactory bowel preparation based on OBPS between the two groups when receiving same preparation formula (polyethylene glycol) (OR 0.83; 95%CI: 0.51-1.35; P = 0.46; I² = 39%) as well as receiving same formula and volume (4 L polyethylene glycol) (OR 1.14; 95%CI: 0.65-2.01; P = 0.64; I² = 0%).

CONCLUSION

In patients undergoing afternoon colonoscopies, SaD is comparable with SpD in terms of satisfactory bowel preparation. Further studies are needed to validate these results and determine the optimal formula and dosages.

The Bowel CLEANsing National Initiative: A Low-Volume Same-Day Polyethylene Glycol (PEG) Preparation vs Low-Volume Split-Dose PEG With Bisacodyl or High-Volume Split-Dose PEG Preparations-A Randomized Controlled Trial

INTRODUCTION

Bowel cleanliness has been shown to be superior with split-dose vs nonsplit preparations; we aimed to directly assess the poorly characterized comparative efficacies of split-dose vs same-day polyethylene glycol (PEG) regimens.

METHODS

In this study, one of a series of randomized trials performed across 10 Canadian endoscopy units, patients undergoing colonoscopies between 10:30 and 16:30 were allocated to PEG low-volume same-day (15 mg bisacodyl the day before, 2 L the morning of the procedure), low-volume split-dose (15 mg bisacodyl the day before, 1 L + 1 L), or high-volume split-dose (2 L + 2 L). Coprimary endpoints were adequate bowel cleansing based on the Boston Bowel Preparation Scale using in turn different threshold cutoffs.

RESULTS

Overall, 1,750 subjects were randomized equally across the 3 groups, with no differences in adequate bowel cleanliness rates (low-volume same-day, 90.5%; high-volume split-dose, 92.2%; P = 0.34; and low-volume split-dose, 87.9%; P = 0.17) for the Boston Bowel Preparation Scale ≥6 and 2 for each segment. Willingness to repeat the preparation was not significantly different between low-volume same-day (91.0%) and low-volume split-dose (92.5%; P = 0.40) but was greater than the high-volume split-dose (68.9%; P < 0.01). No significant differences were noted for withdrawal time, cecal intubation, or polyp detection rates.

DISCUSSION

In this large randomized trial of PEG regimens, low-volume same-day resulted in similar bowel cleanliness compared with high-volume or low-volume split-dosing. Willingness to repeat and tolerability were superior with low-volume same-day compared with high-volume split-dose and similar to low-volume split-dose.

Randomized Controlled Trial: Split-dose and Same-day Large Volume Bowel Preparation for Afternoon Colonoscopy Have Similar Quality of Preparation

GOALS

We compare bowel cleanliness in patients taking same-day versus split-dose 4-L polyethylene glycol laxative for afternoon colonoscopy. Secondary objectives included patient satisfaction, adverse effects and patient tolerability.

BACKGROUND

Afternoon colonoscopies have been associated with inadequate bowel preparation and lower adenoma detection rates. Same-day (morning) or split-dosing of the laxative have improved preparation quality but differences between these options are unclear.

MATERIALS AND METHODS

Single-center prospective randomized endoscopist blinded trial. Patients aged 18 years and above prescribed 4-L polyethylene glycol for colonoscopy were randomized into same-day or split-dose preparation. Preparation quality was assessed using the Ottawa Bowel Preparation Scale. Patient satisfaction and side effects was collected using a questionnaire. Intention-to-treat and per-protocol analysis were performed.

RESULTS

A total of 300 patients (158 split-dose, 142 same-day) were evaluated. No statistically significant difference was seen on total Ottawa score among the groups (P=0.47) or by individual colonic segments in intent-to-treat and per-protocol analysis. Patients in split-dose group were more likely to complete the entire preparation (P=0.01) but reported more sleep loss (P=0.001). The same-day preparation group reported higher incidence of vomiting (P=0.036). Patients ingesting bowel preparation ≥7 hours before colonoscopy had higher total Ottawa scores (P=0.001).

CONCLUSIONS

There were no differences in quality of preparation in patients taking same-day versus split-dose preparation for afternoon colonoscopy. Those receiving same-day preparation were less likely to lose sleep but more likely to have emesis. These differences should be considered when selecting a bowel preparation regimen.

The Efficacy of Split-Dose Bowel Preparations for Polyp Detection: A Systematic Review and Meta-Analysis

INTRODUCTION

Split-dose bowel preparation leads to superior colon cleansing for colonoscopy. However, the magnitude of benefit in detecting colonic polyps is uncertain. We performed a systematic review to synthesize the data on whether using a split-dose bowel preparation regimen improves the detection of polyps when compared with other dosing methods or regimen products.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL databases (from the inception to June 2017) for randomized controlled trials that assessed the following: split-dose vs day-before, split-dose vs same-day (as colonoscopy), or different types of split-dose regimens for patients undergoing colonoscopy. We excluded studies limited to inpatients, children, or individuals with inflammatory bowel disease. We compared the number of patients undergoing colonoscopy with recorded detection of polyps, adenomas, advanced adenomas, sessile serrated polyps (SSPs), right colonic adenomas, right colonic polyps, or right colonic SSPs.

RESULTS

Twenty-eight trials fulfilled the inclusion criteria (8,842 participants). Of the seven trials comparing split-dose vs day-before bowel preparation regimens, there was an increased detection rate of adenomas (risk ratio (RR) 1.26, 95% confidence intervals (CIs): 1.10-1.44; 4 trials; 1,258 participants), advanced adenomas (RR 1.53, 95% CI: 1.22-1.92; 3 trials; 1,155 participants), and SSPs (RR 2.48, 95% CI: 1.21-5.09; 2 trials; 1,045 participants). Pooled estimates from 8 trials (1,587 participants) evaluating split-dose vs same-day bowel preparations yielded no evidence of statistical difference. For various split-dose vs split-dose trials, 14 fulfilled the criteria (5,496 participants) and no superior split-regimen was identified.

CONCLUSIONS

Compared with day-before bowel preparation regimens, split-dose bowel preparations regimens increase the detection of adenomas, advanced adenomas, and have the greatest benefit in SSP detection.

Same-Day Regimen as an Alternative to Split Preparation for Colonoscopy: A Systematic Review with Meta-Analysis

Background

Split bowel preparation is the best regimen for colonoscopy. However, the same-day regimen can represent a valid alternative, but its use is limited by concerns about its cleansing ability, and to date, no convincing data support its use for routine colonoscopies.

Aim

To evaluate the cleansing, compliance, and adverse event rates of the same-day compared to the split regimen.

Results

A systematic literature search and meta-analysis was performed. Ten studies were included for a total of 1807 patients (880 in the same-day group and 927 in the split group). Overall, 85.3% patients in the same-day group vs. 86.3% in the split group had an adequate cleansing. Compliance was high for both, although patients were more compliant with the split than with the same-day prep (89.7% for same-day vs. 96.6% for split regimen). Sleep disturbance was more frequent in the split group, while nausea and vomit were more frequent in the same-day group. In the subgroup analysis, polyethylene glycol obtained a better cleansing rate when given as a split dose, with similar compliance and adverse events rates with both regimens.

Conclusion

Split and same-day regimens are both useful in bowel cleaning before colonoscopy with a different pattern of adverse events and better compliance for split preparations. Endoscopists can consider the same-day preparation as a valid alternative, especially when the split preparation does not fit the patients' needs.

Preparation for colonoscopy: Recommendations by an expert panel in Italy

BACKGROUND

Despite several guidelines on bowel preparation being available, their applicability in Italy is poorly investigated.

AIMS

(1) To create expert-based recommendations for the Italian setting based on available international guidelines on bowel preparation for colonoscopy; (2) to assess consensus across the Italian endoscopy community.

METHODS

The study was conducted in 2 phases: (a) statements formulation, (b) assessment of consensus. For the first phase, 6 topics related to bowel preparation were identified: (1) efficacy/tolerability; (2) timing; (3) assessment of quality of bowel preparation; (4) factors associated with inadequate preparation; (5) patient education and (6) impact of organisational factors. For each topic, statements were produced and voted by a panel of experts. For consensus assessment, the invited participants were asked to rate the statements. The statement achieved a good level of agreement when at least 70% of voters agreed with it.

RESULTS

25 statements were agreed in the first phase. Agreement was not achieved by the endoscopy community for 7 statements, mainly concerning practical aspects (i.e. strategies for management of patients with inadequate preparation, organisational factors).

CONCLUSION

A clinically relevant consensus was achieved on the main topics of bowel preparation, such as the choice of laxative and the time of administration, and it may help to homogenize the colonoscopy practice in Italy. Nevertheless, there are a few country-specific preparation-related issues that need to be addressed.

Bowel Preparations Administered the Morning of Colonoscopy Provide Similar Efficacy to a Split Dose Regimen: A Meta Analysis

BACKGROUND

Comparative efficacy of same-day bowel preparations for colonoscopy remains unclear.

AIMS

A meta-analysis of randomized controlled trials comparing the efficacy of same-day versus split dose bowel preparations for colonoscopy.

METHODS

A systematic search was conducted in MEDLINE, clinicaltrials.gov, Cochrane Registry, EMBASE, SCOPUS, Web of Science and CINAHL. Studies were gathered using keywords: "morning preparation", "morning bowel preparation", "same day bowel preparation", and "colonoscopy." Pooled estimates of bowel preparation quality were analyzed among studies with categorical and continuous outcomes according to relative risk (RR) or mean difference (MD). A random effects model was chosen a priori for all analyses.

RESULTS

A total of 1216 studies were retrieved with 15 trials meeting inclusion criteria. The categorical outcome of high quality bowel preparation for any same-day bowel preparation versus any split preparation was no different with a RR 0.95 [0.90;1.00] (P=0.62). Adenoma detection rate (ADR) was not different between groups, RR 0.97 [0.79;1.20] (P=0.81). Willingness to repeat and tolerability did not differ (RR 1.14 [0.96,1.36] (P=0.14) and RR 1.00 [0.96;1.04] (P=0.98), respectively. Adverse events were similar except for bloating, which was less frequent among the same-day preparation group, RR 0.68 [0.40;0.94] (P=0.02).

CONCLUSION

No clinically significant differences were noted among recipients of same day or split dose regimens. Adenoma detection rate, willingness to repeat and tolerability were similar, but bloating and interference with sleep favored the same-day preparations. Given lack of clinical differences, patient preference should dictate timing of colonoscopy preparation.

Polyethylene glycol plus bisacodyl: A safe, cheap, and effective regimen for colonoscopy in the South Asian patients

Background and Aim

Data regarding the comparison of colonoscopic preparation regimens are still variable. We aimed to assess the adequacy and tolerability of two bowel preparation regimens for afternoon colonoscopy.

Methods

In a randomized, investigator‐blinded trial, two preparation regimens [4‐L split‐dose polyethylene glycol‐electrolytes (PEG‐ELS) and 2‐L PEG‐ELS plus bisacodyl) were compared in terms of bowel cleansing efficacy and adverse effects.

Results

The mean (±SD) age (years) of the 4‐L split‐dose PEG‐ELS group (N = 147) and the 2‐L PEG‐ELS plus bisacodyl (N = 155) were 44.09 (±15.62) (M:F : 2:1) and 44.12 years (±15.61) (M:F : 1.7:1), respectively. Percentage of patients with excellent and good preparation was higher in the 4‐L split‐dose PEG‐ELS regimen compared with the 2‐L PEG‐ELS plus bisacodyl regimen (22.44 vs 17.41 and 44.21% vs 36.12%). Percentage of patients with fair and poor preparation was lower in 4‐L split‐dose PEG‐ELS regimen compared with the 2‐L PEG‐ELS plus bisacodyl regimen (21.08% vs 27.74% and 12.24% vs 18.70%). In comparison with the 2‐L PEG‐ELS plus bisacodyl group, the incidences of abdominal pain (11% vs 15%), bloating (9% vs 12.24%), nausea/vomiting (8.38% vs 9.52%), and sleep disturbance (11% vs 12%) were slightly more common in the 4‐L split‐dose PEG‐ELS group. There were no statistically significant differences between the two regimens with regard to bowel cleansing efficacy and adverse events.

Conclusions

The 2‐L PEG‐ELS plus bisacodyl (10 mg) preparation is as efficacious as the 4‐L split‐dose PEG‐ELS regimen for afternoon colonoscopy. Optimal preparation for colonoscopy can be achieved with the 2‐L PEG‐ELS plus bisacodyl regimen with slightly fewer adverse events and lower cost compared to the 4‐L split‐dose PEG‐ELS regimen.

Same-day Versus Split-dose Bowel Preparation Before Colonoscopy: A Meta-analysis

BACKGROUND

Split-dose regimens (SpDs) were recommended as a first choice for bowel preparation, whereas same-day regimens (SaDs) were recommended as an alternative; however, randomized trials compared them with mixed results. The meta-analysis was aimed at clarifying efficacy level between the 2 regimens.

MATERIALS AND METHODS

We used MEDLINE/PubMed, EMBASE, Scopus, CINAHL, Cochrane Library, and Web of Science to identify randomized trials published from 1990 to 2016, comparing SaDs to SpDs in adults. The pooled odds ratios (ORs) were calculated for preparation quality, cecal intubation rate (CIR), adenoma detection rate (ADR), and any other adverse effects.

RESULTS

Fourteen trials were included. The proportion of individuals receiving SaDs and SpDs with adequate preparation in the pooled analysis were 79.4% and 81.7%, respectively, with no significant difference [OR=0.92; 95% confidence interval (CI), 0.62-1.36] in 11 trials. Subgroup analysis revealed that the odds of adequate preparation for SaDs with bisacodyl were 2.45 times that for SpDs without bisacodyl (95% CI, 1.45-4.51, in favor of SaDs with bisacodyl). Subjects received SaDs experienced better sleep.

CONCLUSIONS

SaDs were comparable with SpDs in terms of bowel cleanliness, CIR, and ADR, and could also outperform SpDs in preparation quality with bisacodyl. SaDs also offered better sleep the previous night than SpDs did, which suggests that SaDs might serve as a superior alternative to SpDs. The heterogenous regimens and measurements likely account for the low rates of optimal bowl preparations in both arms. Further studies are needed to validate these results and determine the optimal purgatives and dosages.

Same-Day Single Dose of 2 Liter Polyethylene Glycol is Not Inferior to The Standard Bowel Preparation Regimen in Low-Risk Patients: A Randomized, Controlled Trial

OBJECTIVES

Split dose of 4 l polyethylene glycol (PEG) is currently the standard regimen for bowel preparation (BP). However, it may be unnecessary for patients without high risks (e.g., old age, constipation, and diabetes, and so on) for inadequate BP. The study aimed to compare the efficacy of bowel cleansing between low-risk patients receiving same-day, single dose of low-volume (SSL) PEG vs. standard regimen.

METHODS

This prospective, randomized, observer-blinded, non-inferiority study enrolled low-risk patients in three centers. Patients undergoing colonoscopy were randomized (1:1) to the SSL or standard group. The primary outcome was adequate BP, defined by Boston Bowel Preparation Score (BBPS) ≥6 and each segmental score ≥2. Secondary outcomes included adverse events, cecal intubation rate, and patient willingness to repeat BP, and so on.

RESULTS

Among 2,532 patients eligible for the study, 940 (37.1%) were at low risk and 792 (31.3%) at high risk for inadequate BP. The low-risk patients were randomly allocated to the SSL (n=470) or standard group (n=470). The baseline characteristics of the two groups were similar. Intention-to-treat analysis showed that adequate BP was achieved in 88.1% in the SSL group and 87.0% in the standard group (relative risk (RR) 1.10, 95% confidence interval (CI): 0.75-1.63, P=0.621). The overall BBPS was 7.3±1.2 and 7.3±1.3, respectively (P=0.948). No significant differences were found between the two groups with regards to the right, transverse, and left-segmental colon BBPS (all P>0.05). However, in terms of adverse events, patients in the SSL group reported less nausea (19.6% vs. 29.9%), vomiting (5.3% vs. 11.4%), and abdominal discomfort (2.2% vs. 6.0%) compared with those in the standard group. More patients in the SSL group were willing to repeat BP (94.0% vs. 89.5%, P=0.015).

CONCLUSIONS

For low-risk patients, the SSL regimen was not inferior to the split dose of 4 l PEG for adequacy of BP. Single dose of low-volume regimen had significantly fewer adverse events. This simplified regimen may be preferable in the "easy-to prepare" population.

Safety and Efficacy of a Same-Day Low-Volume 1 L PEG Bowel Preparation in Colonoscopy for the Elderly People and People with Renal Dysfunction

INTRODUCTION

A same-day low-volume 1 L polyethylene glycol (PEG) for bowel preparation before colonoscopy was developed to improve patients' compliance. We aimed to evaluate the efficacy and safety of this regimen especially for the elderly and patients with renal dysfunction.

METHODS

All consecutive patients who underwent colonoscopy in our center from November 2014 to September 2015 were included. Patients undertook a low-residue diet with 10 mL sodium picosulfate 1 day before colonoscopy. Subsequently, they had 1 L low-volume PEG (MoviPrep) and 0.5 L water 4 h before the examination. Clinical outcomes, including cleansing level using the Boston bowel preparation score (BBPS), in the elderly and special-elderly (65-79 and ≥80 years old) were analyzed and compared with the non-elderly (18-64 years old). Additionally, patients with renal dysfunction were analyzed with respect to both complications and changes in blood parameters.

RESULTS

A total of 5427 patients (mean age: 64.5 ± 13.8) were analyzed. The rate of BBPS ≥ 6 in the elderly (2761 patients), special-elderly (565 patients), and non-elderly (2101 patients) was 94.1, 91.8, and 94.6 %, respectively. In the special-elderly, the rate of renal dysfunction was 14.8 %, and no severe complications were detected after colonoscopy. Additionally, there were no severe complications in 86 patients with renal dysfunction, though elevation of hematocrit was shown after intake of 1 L PEG (before, 36.7 ± 6.1 vs. after, 39.0 ± 5.7, P = 0.006).

CONCLUSIONS

Our study shows the safety and efficacy of same-day low-volume 1 L PEG bowel preparation in colonoscopy for the elderly and patients with renal dysfunction.

Low-residue versus clear liquid diet before colonoscopy: a meta-analysis of randomized, controlled trials

BACKGROUND AND AIMS

Colonoscopy is extremely important for the identification and removal of precancerous polyps. Bowel preparation before colonoscopy is essential for adequate visualization. Traditionally, patients have been instructed to consume only clear liquids the day before a colonoscopy. However, recent studies have suggested using a low-residue diet, with varying results. We evaluated the outcomes of patients undergoing colonoscopy who consumed a clear liquid diet (CLD) versus low-residue diet (LRD) on the day before colonoscopy by a meta-analysis.

METHODS

Scopus, PubMed/MEDLINE, Cochrane databases, and CINAHL were searched (February 2015). Studies involving adult patients undergoing colonoscopy examination and comparing LRD with CLD on the day before colonoscopy were included. The analysis was conducted by using the Mantel-Haenszel or DerSimonian and Laird models with the odds ratio (OR) to assess adequate bowel preparations, tolerability, willingness to repeat diet and preparation, and adverse effects.

RESULTS

Nine studies (1686 patients) were included. Patients consuming an LRD compared with a CLD demonstrated significantly higher odds of tolerability (OR 1.92; 95% CI, 1.36-2.70; P < .01) and willingness to repeat preparation (OR 1.86; 95% CI, 1.34-2.59; P < .01) with no differences in adequate bowel preparations (OR 1.21; 95% CI, 0.64-2.28; P = .58) or adverse effects (OR 0.88; 95% CI, 0.58-1.35; P = .57).

CONCLUSION

An LRD before colonoscopy resulted in improved tolerability by patients and willingness to repeat preparation with no differences in preparation quality and adverse effects.

The White Diet is preferred, better tolerated, and non-inferior to a clear-fluid diet for bowel preparation: A randomized controlled trial

BACKGROUND AND AIM

Dietary restrictions contribute to the unpleasantness of bowel preparation for colonoscopy. We compare the effectiveness and tolerability of a low residue diet of white-colored foods ("White Diet") with a clear-fluid diet the day prior to colonoscopy in an endoscopist-blinded randomized non-inferiority trial.

METHODS

Adults undergoing outpatient colonoscopy were randomized with stratification by procedure timing to a White Diet or clear-fluid diet. All received a 2-L polyethylene glycol lavage solution with ascorbate, sodium sulfate, and electrolytes, the day-before for morning and as a split-dose for afternoon procedures. The primary end-point was successful bowel preparation (A or B on the Harefield Cleansing Scale). Regimen tolerance/acceptance was assessed by questionnaire. An intention-to-treat analysis with a predefined non-inferiority margin of 15% was used to compare efficacy.

RESULTS

A total of 226 patients (average age 52 years, 51% male) were randomized (111 clear diet, 115 White Diet). Bowel preparation was successful in 91% on the clear-fluid diet vs 84.4% on the White Diet, difference being -6.6% (lower one sided 95% CI -13.8%), with no difference according to diet. The split-dose regimen (in 55%) had a higher success rate than day-before regimen (96% vs 80%, p < 0.001). The White Diet was preferred with less hunger and interference with daily activities (p < 0.001). Procedural/withdrawal time and polyp/adenoma detection were similar between groups.

CONCLUSIONS

The White Diet was preferred and better tolerated by patients without detriment to the success of bowel preparation or colonoscopy performance, especially with the split-dose regimen.

Body mass index and quality of bowel preparation: Real life vs. clinical trials

BACKGROUND AND STUDY AIMS

Obesity is a recognised risk factor for poor bowel preparation in retrospective studies whilst corresponding data in prospective trials are marginally reported. Aims are to evaluate the relation between body mass index (BMI) and preparation quality in retrospective and interventional prospective settings and within a single centre.

PATIENTS AND METHODS

Data from a recent colorectal cancer screening registry were retrospectively analysed for the relation between BMI and adequacy of preparation. Patients were categorised as underweight (BMI<20kg/m(2)), normal (20-25kg/m(2)), overweight (25-30kg/m(2)), and obese (>30kg/m(2)). Data from a recent prospective colon preparation trial were similarly analysed.

RESULTS

541 registry patients were included. Multivariate analysis showed BMI to be an independent risk factor for inadequate preparation. Obesity was associated with odds ratio (OR) of 5.3 [95% confidence interval (CI) 1.4-19.8; p=0.01] compared to normal BMI. A significant difference was also noted in underweight but otherwise healthy individuals (OR=11.1, 95% CI 2-60; p=0.005). In the prospective study of 195 patients, obese patients had comparable rates of inadequate preparation to normal-weight individuals (OR=0.7, 95% CI 1.1-3.96; p=0.68). Underweight patients had a significantly worse preparation compared to normal BMI individuals (OR=8, 95% CI 1.1-58; p=0.04).

CONCLUSIONS

In real life, bowel preparations in obese individuals have a lower quality in comparison to normal individuals. This finding is not replicated in clinical trials. This discrepancy is likely the result of focused patient education suggesting that this is primarily a dietary compliance phenomenon. Underweight individuals appear to have worse quality of preparation independent of study design or setting.