Efficacy of prepackaged, low residual test meals with 4L polyethylene glycol versus a clear liquid diet with 4L polyethylene glycol bowel preparation: a randomized trial

One-Day versus Three-Day Low-Residue Diet and Bowel Preparation Quality before Colonoscopy: A Multicenter, Randomized, Controlled Trial

BACKGROUND

One-day low-residue diet (LRD) is recommended before colonoscopy, but only three single-center trials compared the 1-day versus 3-day LRD. The aim of this multicenter study was to compare the impact of a 3-day versus 1-day LRD on its ability to adequately and successfully prepare the bowel of outpatients that require a colonoscopy. The outpatients' tolerance and adherence to the LRD were also considered.

METHODS

Consecutive outpatients were randomized to 1-day versus 3-day LRD at three open-access endoscopy units. The primary endpoint consisted of the proportion of patients with a satisfactory degree of bowel cleanliness (Score 2-3 on the Boston Bowel Preparation Scale [BBPS] in each segment). Secondary endpoints were patients' tolerance and adherence to the prescribed diet evaluated by a standardized questionnaire.

RESULTS

289 patients were included in the study (1-day LRD arm = 143, 3-day LRD arm = 146). BBPS ≥2 was not significantly different in the two dietary regimens in any of the three colonic segments (71% vs. 72%, p = 0.9). The percentage of patients with incomplete preparation was similar in the two arms (9% vs. 9%; p = 1.0). No significant differences were found among colonoscopy findings in terms of abnormalities (81% vs. 84%, p = 0.8). Both groups scored similarly in overall tolerance to LRD (48% vs. 49%, p = 1.0) and also in whether they would have adopted a different dietary regimen (p = 0.3).

CONCLUSION

Our multicenter randomized study confirmed that optimal bowel cleansing is reached through a 1-day LRD.

Efficacy and tolerability of a low-residue diet for bowel preparation: systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) contributes significantly to cancer mortality worldwide. In an effort to reduce the risk of death, detection of polyps through colonoscopy is crucial. The success of the colonoscopy depends on the diet administered the day before the test. Our aim was to evaluate the efficacy, tolerability, and adverse effects of bowel preparation when using a low-residual diet (LRD) compared to a clear-liquid diet (CLD) the day before a scheduled colonoscopy.

METHODS

PubMed/Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL) and Scopus databases were searched. We included studies of patients undergoing a scheduled colonoscopy for CRC screening and surveillance or for diagnostic purposes that compared a LRD with a CLD the day before the colonoscopy. Efficacy, the primary outcome, was evaluated as the rate of adequate bowel preparation. Secondary outcomes were tolerability and adverse effects of bowel preparation.

RESULTS

Thirteen RCTs (N = 2587) were included. Patients receiving a LRD compared to a CLD showed no difference in adequate bowel preparations (RR 1.02; 95% CI 0.99-1.05; I² = 60%). However, the LRD improved patient tolerability (RR 1.17; 95% CI 1.12-1.23; I² = 66%) and had fewer adverse effects (RR 0.89; 95% CI 0.84-0.94; I² = 73%) compared to the CLD. Groups using a LRD with 4L of polyethylene glycol in a single dose or a LRD with < 2000 kcal < 32 g of fibres/day had better tolerability.

CONCLUSION

Based on these findings, our recommendation is strong in favour of a LRD for bowel preparation of patients undergoing a scheduled colonoscopy. This diet could also be useful as a preoperative colonic preparation, but this requires further research.

Single-Day Low-Residue Diet Prior to Colonoscopy Demonstrates Improved Bowel Preparation Quality and Patient Tolerance over Clear Liquid Diet: A Randomized, Single-Blinded, Dual-Center Trial

BACKGROUND AND AIMS

Patients often refer to bowel preparation and associated dietary restrictions as the greatest deterrents to having a colonoscopy completed or performed. Large studies comparing a low-residue diet (LRD) and a clear liquid diet (CLD) are still limited. The aim of this study is to compare LRD and CLD with regard to bowel preparation quality, tolerance, and satisfaction among a diverse patient population.

METHODS

This study is a dual-center, randomized, single-blinded, prospective trial involving adult patients undergoing outpatient colonoscopy at the University of California Irvine Medical Center and an affiliated Veterans Administration hospital. Patients were randomized to consume either a CLD or a planned LRD for the full day prior to colonoscopy. Both groups consumed 4L split-dosed PEG-ELS. The adequacy of bowel preparation was evaluated using the Boston Bowel Preparation Score (BBPS). Adequate preparation was defined as a BBPS ≥ 6 with no individual segment less than a score of 2. Hunger and fatigue pre - and post-procedure were graded on a ten-point scale. Nausea, vomiting, bloating, abdominal cramping, overall discomfort, satisfaction with the diet, willingness to repeat the same preparation and overall experience were assessed.

RESULTS

A total of 195 subjects who underwent colonoscopy from October 2014 to October 2017 were included. The mean BBPS for the LRD and CLD groups was 8.38 and 7.93, respectively (p = 0.1). There was a significantly higher number of adequate preparations in the LRD group compared to CLD (p = 0.05). Evening hunger scores just before starting the bowel preparation were significantly lower in the LRD than the CLD group, 2.81 versus 5.97, respectively (p = 0.006). Subjects in the LRD group showed significantly less nausea (p = 0.047) and bloating (p = 0.04). Symptom scores for vomiting, abdominal cramping, and overall discomfort were similar between the groups. Satisfaction with diet was significantly higher in the LRD group than CLD, 72% versus 37.66%, respectively (p < 0.001). The overall colonoscopy experience and the satisfaction with the preparation itself were also better reported in the LRD group (p < 0.001 and p = 0.002, respectively).

CONCLUSIONS

This study, which included a diverse group of patients, demonstrated that patients using a LRD before colonoscopy achieve a bowel preparation quality that is superior to patients on a CLD restriction. This study shows that a low-residue diet improves patient satisfaction and results in significantly better tolerability of bowel preparation. As a less restrictive dietary regimen, the low-residue diet may help improve patient participation in colorectal cancer screening programs.

ESPEN guideline on hospital nutrition

In hospitals through Europe and worldwide, the practices regarding hospital diets are very heterogeneous. Hospital diets are rarely prescribed by physicians, and sometimes the choices of diets are based on arbitrary reasons. Often prescriptions are made independently from the evaluation of nutritional status, and without taking into account the nutritional status. Therapeutic diets (low salt, gluten-free, texture and consistency modified, …) are associated with decreased energy delivery (i.e. underfeeding) and increased risk of malnutrition. The European Society for Clinical Nutrition and Metabolism (ESPEN) proposes here evidence-based recommendations regarding the organization of food catering, the prescriptions and indications of diets, as well as monitoring of food intake at hospital, rehabilitation center, and nursing home, all of these by taking into account the patient perspectives. We propose a systematic approach to adapt the hospital food to the nutritional status and potential food allergy or intolerances. Particular conditions such as patients with dysphagia, older patients, gastrointestinal diseases, abdominal surgery, diabetes, and obesity, are discussed to guide the practitioner toward the best evidence based therapy. The terminology of the different useful diets is defined. The general objectives are to increase the awareness of physicians, dietitians, nurses, kitchen managers, and stakeholders towards the pivotal role of hospital food in hospital care, to contribute to patient safety within nutritional care, to improve coverage of nutritional needs by hospital food, and reduce the risk of malnutrition and its related complications.

A Systematic Review and Meta-Analysis of Low-Residue Diet Versus Clear Liquid Diet: Which Is Better for Bowel Preparation Before Colonoscopy?

The goal of this systematic review was to compare the clear liquid diet and the low-residue diet to determine which is better for bowel preparation before colonoscopy. A literature search for randomized controlled trials on the effects of employing the clear liquid diet and low-residue diets before colonoscopy was conducted in major online English databases (PubMed, Web of Science, and Ovid EMBASE). After the systematic review of all 16 studies, the outcomes including quality of bowel preparation, tolerance, willingness to repeat, and adverse effects were analyzed through meta-analysis. The statistical analysis was performed by using RevMan 5.3 software. No statistically significant difference was observed between the low-residue diet and clear liquid diet groups (odds ratio [95% confidence interval] = 1.19 [0.79, 1.81]; p = .41). There was no statistically significant difference between the Boston Bowel Preparation Scale (standard mean difference [95% confidence interval] =-0.04 [-0.21, -0.14]; p = .68) Ottawa Bowel Preparation Scale (standard mean difference [95% confidence interval] =-0.04 [-0.19, 0.11]; p = .59) scores of the two groups. The quality indicators for colonoscopy of the two groups were not statistically significant. However, patient tolerance to the low-residue diet was higher (odds ratio [95% confidence interval] = 1.86 [1.47, 2.36]; p < .01). More patients in the low-residue diet group were willing to repeat the low-residue diet for bowel preparation (odds ratio [95% confidence interval] = 2.34 [1.72, 3.17]; p < .01). More patients in the clear liquid diet group experienced hunger, nausea, and vomiting. People who employed the low-residue diet before colonoscopy had the same quality of bowel preparation as those with clear liquid diet. Meanwhile, the tolerance of people with low-residue diet was better than people with clear liquid diet, and these people were more willing to repeat the colonoscopy with less adverse events.

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.

Efficacy of low residue enteral formula versus clear liquid diet during bowel preparation for colonoscopy: a randomised controlled pilot trial

Objectives Conventional bowel preparation for colonoscopy confines patient to clear liquid diet the day before and such non-nutritive dietary regimen often caused discomfort and hunger. The purpose of this study is to determine the feasibility of feeding patient with low-residue, lactose-free semi-elemental enteral formula (PEPTAMEN®) compare to conventional clear liquid diet during bowel preparation before colonoscopy.

Methods This was a randomised, endoscopist-blinded study. Patients were randomised into two groups, those receiving oral PEPTAMEN® and mechanical bowel preparation (A) and those receiving clear liquid while undergoing mechanical bowel preparation (B). Documentation was made with regard to the type of bowel cleansing agents used, completeness of the colonoscopy, cleanliness quality score, and hunger score.

Results A total of 97 patients were included in the study, A = 48 and B = 49. Eight patients, who were not compliant to the bowel-cleansing agent or had an incomplete colonoscopic examination, were excluded from the study. In terms of the overall cleanliness score, no statistical significant difference was seen (p = 0.25) between the two groups, A (fair or poor 37.5%, good or excellent 62.5%) and B (fair or poor 49%, good or excellent 51%) whereas the hunger score showed a significant difference (p = 0.016), A (no hunger 41.7%, slight hunger 12.5%, hungry 12.5%) and B (no hunger 24.5%, slight hunger 38.8%, hungry 36.7%).

Conclusions These data suggest that the addition of oral PEPTAMEN® as part of the bowel preparation regimen did not significantly alter the luminal cleanliness score during colonoscopy while alleviating hunger.

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

Great value in the early identification and treatment of adenomatous polyps or early canceration using colonoscopy has been recognized. A clear colonoscopic vision brought by good intestinal preparation will become crucial. Several studies have completed using the low-residue diet (LRD) versus a clear liquid diet (CLD) the day before colonoscopy that presenting contradictory results. Therefore, a more comprehensive and updated meta-analysis is needed to summarize the findings on the effects of LRD and CLD on intestinal preparation and the quality of coloscopy.The comprehensive search was performed in PubMed/MEDLINE, Scopus, Cochrane databases (February 2020). LRD vs CLD before colonoscopy were included in this study. Mantel-Haenszel or DerSimonian and Laird models with the relative risk (RR) to evaluate differences in intestinal preparation, tolerance, readiness to repeat preparation, detected of a polyp, and overall adverse reactions.Total 16 studies (N = 3413) were eligible. Patients with LRD compared with CLD indicated significantly better of tolerability (RR 0.92;95% CI,0.85-0.99; P < .05) and willingness to repeat intestinal preparation (RR 0.86; 95% CI 0.79-0.93; P < .05), but no differences with adequate intestinal preparations, detected polyp or overall adverse reactions (all P > .05).Patients with LRD the day before colonoscopy show better tolerance and willingness to repeat intestinal preparation, and no difference with adequate intestinal preparations compared with CLD, but the recommended level of evidence is weak. However, in terms of the detection rate of intestinal adenomas, the LRD group is not weaker than the CLD group, for its evidence level is high, and can significantly reduce the hunger experience of patients.

Low-residual diet versus clear-liquid diet for bowel preparation before colonoscopy: meta-analysis and trial sequential analysis of randomized controlled trials

BACKGROUND AND AIMS

The aim of this study was to compare a low-residual diet (LRD) with a clear-liquid diet (CLD) for bowel preparation before colonoscopy.

METHODS

A systematic literature search was performed in PubMed, Ovid, and Cochrane databases for randomized clinical trials comparing LRD with CLD for bowel preparation before colonoscopy. The last search was performed on September 20, 2019. The primary outcome was adequate bowel preparation. The outcomes were compared using systematic review with meta-analysis and trial sequential analysis (TSA).

RESULTS

Twenty randomized controlled trials published between 2005 and 2019 with 4323 participants were included. LRD was comparable with CLD for adequate bowel preparation (P = .79; odds ratio [OR], 0.96; 95% confidence interval [CI], 0.72-1.29). The detection rates for polyps (P = .68; OR, 1.04; 95% CI, 0.86-1.27) or adenomas (P = .78; OR, 1.03; 95% CI, 0.86-1.23) were similar between the groups. There were significantly fewer advents in individuals in the LRD group: nausea (P = .02; OR, 0.72; 95% CI, 0.56-0.94), vomiting (P = .04; OR, 0.61; 95% CI, 0.38-0.98), hunger (P < .001; OR, 0.36; 95% CI, 0.24-0.53), and headache (P = .02; OR ,0.64; 95% CI, 0.44-0.93). In addition, significantly more individuals in the LRD group found it easy to complete the diet (P = .01; OR, 1.86; 95% CI, 1.15-3.00) and showed willingness to repeat it (P = .005; OR, 2.23; 95% CI, 1.28-3.89). TSA demonstrated that the cumulative Z curve crossed both the traditional boundary and the trial sequential monitoring boundary for adequate bowel preparation.

CONCLUSION

The present study demonstrated that LRD was comparable with CLD in the quality of bowel preparation before colonoscopy. More clinical trials are needed to confirm other outcomes.

Effect of the High-FODMAP Diet on Bowel Preparation for Colonoscopy: A Multicenter, Prospective Cohort Study

Background

Optimal bowel preparation for colonoscopy is fundamental to a successful examination. The FODMAP diet can increase the content of intestinal water and gas, but its impact on bowel cleanliness and bubbles has not been reported. This study was therefore aimed at evaluating the effect of the FODMAP diet on the quality of bowel preparation and the adenoma detection rate (ADR).

Methods

This was a multicenter, prospective cohort study involving consecutive patients who underwent colonoscopy in two centers in China. Patients were assigned to one of two groups: high-FODMAP or nonhigh-FODMAP diet. ODMP Software was used for the identification of FODMAP diet types. The primary outcome was ADR; secondary outcomes were the quality of bowel preparation, measured by the Boston bowel preparation scale and bubble scores.

Results

There were 365 patients included. Patients in the high-FODMAP-diet group showed poor bowel cleansing efficacy: BBPS ≥ 6 in 76.8% vs. 90.3% (P < 0.01) and bubble scores of 2.42 ± 1.69 vs. 1.32 ± 1.63 (P < 0.001). The intubation time was significantly longer in the high-FODMAP-diet group (7.07 ± 5.18 vs. 5.46 ± 3.05 min; P = 0.002). The High-FODMAP diet was an independent risk predictor for inadequate bowel preparation. There were no statistically significant differences in ADR between the two dietary groups.

Conclusion

The high-FODMAP diet significantly reduced the quality of bowel preparation. We recommend the consumption of nonhigh-FODMAP diet in bowel preparation as a reference standard for dietary regimen. This method was effective, flexible, referable, and well tolerated, which could help to provide patients a valuable dietary guidance in bowel preparation.

A low-residue diet before colonoscopy tends to improve tolerability by patients with no differences in preparation quality: a randomized trial

BACKGROUND

The pre-colonoscopy diet traditionally involves 24 h of a clear liquid diet (CLD) in combination with a lavage solution; however, this preparation is poorly tolerated.

AIM

To compare the impact on the quality of bowel cleansing and tolerability of a CLD versus a low-residue diet (LRD).

METHODS

We performed a randomized trial. Subjects were randomized to CLD or LRD the day before of elective colonoscopy. All subjects received a 4-L preparation of single-dose PEG beginning 16 h prior to colonoscopy. The Boston bowel preparation scale was used to evaluate bowel cleansing; an adequate-quality preparation was defined as a score ≥ 2 per segment.

RESULTS

A total of 205 subjects were included with a mean age (SD) of 55.6 (12.6) years; 133 (64.9%) of them were female. A total of 105 subjects were randomized to receive CLD and 100 to LRD. No significant differences in bowel preparation quality were observed between groups according to the section of colon: right colon (70% vs. 73%, p = 0.08), transverse colon (82% vs. 79%, p = 0.062), or left colon (80% vs. 78.7%, p = 0.28). There was a tendency toward less-frequent nausea (p = 0.08) and vomiting (p = 0.07) in patients with LRD. No differences between groups regarding ADR (12% vs. 10%) were noted.

CONCLUSIONS

An LRD before colonoscopy resulted in a tendency toward improved tolerability by patients, with no differences in the quality of bowel preparation.

Favorable outcomes of prepackaged low-residue diet on bowel preparation for colonoscopy: Endoscopist-blinded randomized controlled trial

BACKGROUND AND AIM

2 L polyethylene glycol plus an ascorbic acid (PEGA) is known to be as effective. However, 2 L polyethylene glycol-based regimens are often still difficult for patients to tolerate. Therefore, we conducted this study to evaluate the potential of 1 L PEGA with prepackaged low-residue diet (PLD) as an alternative to 2 L PEGA before colonoscopy.

METHODS

The subjects were randomly assigned to either of the two groups. The 2 L PEGA group received 2 L PEGA split regimen. The 1 L PEGA with PLD group received PLD on the day preceding colonoscopy and 1 L PEGA. All endoscopic procedures were performed by one physician who did not know patients allocation. Bowel preparation status were graded using Boston Bowel Preparation Score (BBPS). A questionnaire regarding tolerability and safety was administered. This trial is registered at ClinicalTrials.gov (NCT03329339).

RESULTS

A total of 173 patients completed the study (86 in the 2 L PEGA group and 87 in the 1 L PEGA with PLD group). Bowel preparation was adequate in 88.4% (76/86) of patients in the 2 L PEGA group and 93.1% of patients in the 1 L PEGA with PLD group (81/87, P = 0.28). The patients in the 1 L PEGA with PLD group had higher whole Boston Bowel Preparation Scale score (P = 0.02) and expressed more satisfaction and willingness to repeat the procedure (P < 0.01). There was no significant difference with respect to compliance or safety.

CONCLUSION

1 L PEGA with PLD showed equivalent efficacy, greater satisfaction, and more willingness to repeat compared with 2 L PEGA for bowel preparation.

Randomized Clinical Trial: A Normocaloric Low-Fiber Diet the Day Before Colonoscopy Is the Most Effective Approach to Bowel Preparation in Colorectal Cancer Screening Colonoscopy

BACKGROUND

Clinical guidelines recommend either a clear-liquid diet or a low-fiber diet for colonoscopy preparation. Participants in a screening program are usually motivated healthy individuals in which a good tolerability is important to improve adherence to potential surveillance colonoscopies.

OBJECTIVE

Our aim was to assess whether or not a normocaloric low-fiber diet followed the day before a screening colonoscopy compromises the efficacy of bowel cleansing and may improve the tolerability of bowel preparation.

DESIGN

This is a randomized, endoscopist-blinded, noninferiority clinical trial.

SETTINGS

The study was conducted at a tertiary care center.

PATIENTS

A total of 276 consecutive participants of the Barcelona colorectal cancer screening program were included.

INTERVENTION

Participants were randomly assigned to a clear-liquid diet or a normocaloric low-fiber diet the day before the colonoscopy. Both groups received 4 L of polyethylene glycol in a split-dose regimen.

MAIN OUTCOME MEASURES

Primary outcome was the adequate bowel preparation rate measured with the Boston bowel preparation scale. Secondary outcomes included tolerability, fluid-intake perception, hunger, side effects, and acceptability.

RESULTS

Participants in both groups were similar in baseline characteristics. Adequate bowel preparation was achieved in 89.1% vs 95.7% in clear-liquid diet and low-fiber diet groups, showing not only noninferiority, but also superiority (p = 0.04). Low-fiber diet participants reported less fluid-intake perception (p = 0.04) and less hunger (p = 0.006), with no differences in bloating or nausea.

LIMITATIONS

The single-center design of the study could limit the external validity of the results. The present findings may not be comparable to other clinical settings.

CONCLUSION

A normocaloric low-fiber diet the day before a screening colonoscopy achieved better results than a clear-liquid diet in terms of adequate colon preparation. Moreover, it also improved the perception of hunger and excessive fluid intake. Registered at clinicaltrials.gov: NCT02401802. See Video Abstract at http://links.lww.com/DCR/A829.

Results of a Community-based, Randomized Study Comparing a Clear Liquid Diet With a Low-residue Diet Using a Magnesium Citrate Preparation for Screening and Surveillance Colonoscopies

BACKGROUND

Current bowel preparations for colonoscopy include a clear liquid diet (CLD) along with consumption of a laxative. This dietary restriction along with large volume bowel preparations are barriers to compliance and willingness among patients in scheduling screening examinations. The aim of our study was to compare the efficacy and tolerability of a low-volume split dose magnesium citrate bowel preparation in patients on a low-residue diet (LRD) with those on a CLD.

METHODS

In this single center, single blinded, randomized controlled trial, patients scheduled for outpatient colonoscopies were assigned to either a CLD or a LRD 1 day before the examination. Both groups received a split dose magnesium citrate preparation. The quality of the preparation was rated using the Boston Bowel Preparation Scale (BBPS). Patient satisfaction and side effects were evaluated using a questionnaire.

RESULTS

We were unable to detect a significant difference in the BBPS scores between the LRD and CLD groups (P=0.581). A significantly higher percentage of patients in the LRD group rated the diet as easy compared with the CLD group (P<0.001). Satisfaction scores were significantly higher in the LRD group, compared with the CLD group (P<0.001). The side effect profiles of both arms were similar.

CONCLUSIONS

There was no significant difference between LRD and CLD in patients using a magnesium citrate bowel preparation for screening and surveillance colonoscopies. Patient satisfaction scores were higher with a LRD compared with a CLD. We believe the LRD should be the recommended diet in patients using a standard bowel preparation for screening and surveillance colonoscopy.

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.

Impact of diet restriction on bowel preparation for colonoscopy

Diet restriction is one of the difficult parts of bowel preparation for colonoscopy, and many patients do not follow instructions properly. Few studies have evaluated the impact of dietary restriction in real clinical setting. The aim of this study was to study the effect of diet control on bowel preparation with detailed investigation of unacceptable food list in order to reveal what kind of foods are most problematic in clinical practice.Prospective observational study was carried out at a university-affiliated hospital. Around 4 L polyethylene glycol solution was used for bowel preparation on the day of colonoscopy. Patients were allowed to have regular diet until lunch the day before colonoscopy and educated to control diet from 3 days before colonoscopy with information regarding an unacceptable foods list. Factors associated with inadequate bowel preparation were analyzed using univariate statistics and multivariate logistic regression analysis.Of the 245 patients included in the study, 68 patients (27.8%) followed the diet instructions. Fiber-rich vegetables were the most commonly taken unacceptable foods (N = 143, 58.4%). Inadequate bowel preparation (fair and poor by Aronchick scale) was 47.3%. In multivariate analysis, diabetes [odds ratio (OR) 2.878, 95% confidence interval (CI) 1.242-6.671], preparation to colonoscopy interval (OR 1.003, 95% CI 1.000-1.005) and consumption of foods disturbing bowel preparation (OR 2.142, 95% CI 1.108-4.140) were independent predictors of inadequate bowel preparation.We could identify substantially low compliance to diet instructions in real clinical practice. Consumption of any foods disturbing bowel preparation was significant factor predicting inadequate bowel preparation, even though we could not select specific food list compromising preparation significantly. Favorable bowel preparation was achieved in the subgroup compliant to diet restriction, suggesting that regular diet avoiding specific kinds of foods can be possible option for diet restriction before colonoscopy.

The association among diet, dietary fiber, and bowel preparation at colonoscopy

BACKGROUND AND AIMS

Pre-colonoscopy dietary restrictions vary widely and lack evidence-based guidance. We investigated whether fiber and various other foods/macronutrients consumed during the 3 days before colonoscopy are associated with bowel preparation quality.

METHODS

This was a prospective observational study among patients scheduled for outpatient colonoscopy. Patients received instructions including split-dose polyethylene glycol, avoidance of vegetables/beans 2 days before colonoscopy, and a clear liquid diet the day before colonoscopy. Two 24-hour dietary recall interviews and 1 patient-recorded food log measured dietary intake on the 3 days before colonoscopy. The Nutrition Data System for Research was used to estimate dietary exposures. Our primary outcome was the quality of bowel preparation measured by the Boston Bowel Preparation Scale (BBPS).

RESULTS

We enrolled 201 patients from November 2015 to September 2016 with complete data for 168. The mean age was 59 years (standard deviation, 7 years), and 90% of colonoscopies were conducted for screening/surveillance. Only 17% and 77% of patients complied with diet restrictions 2 and 1 day(s) before colonoscopy, respectively. We found no association between foods consumed 2 and 3 days before colonoscopy and BBPS scores. However, BPPS was positively associated with intake of gelatin, and inversely associated with intake of red meat, poultry, and vegetables on the day before colonoscopy.

CONCLUSIONS

Our findings support recent guidelines encouraging unrestricted diets >1 day before colonoscopy if using a split-dose bowel regimen. Furthermore, we found no evidence to restrict dietary fiber 1 day before colonoscopy. We also found evidence to promote consumption of gelatin and avoidance of red meat, poultry, and vegetables 1 day before colonoscopy.

Lifestyle Factors and Bowel Preparation for Screening Colonoscopy

Purpose

The quality of bowel preparation is a major determinant of the quality of colonoscopy. This study evaluated lifestyle factors, including usual dietary style, associated with bowel preparation.

Methods

This retrospective study evaluated 1,079 consecutive subjects who underwent complete colonoscopy from December 2012 to April 2014 at National Cancer Center of Korea. Questionnaires on bowel preparation were completed by the subjects, with the quality of bowel preparation categorized as optimal (excellent or good) or suboptimal (fair, poor or inadequate). Lifestyle factors associated with bowel preparation were analyzed.

Results

The 1,079 subjects included 680 male (63.0%) and 399 female patietns (37.0%), with a mean age of 49.6 ± 8.32 years. Bowel preparation was categorized as optimal in 657 subjects (60.9%) and as suboptimal in 422 (39.1%). Univariate analyses showed no differences between groups in lifestyle factors, such as regular exercise, alcohol intake, smoking, and dietary factor. Body mass index (BMI) > 25 kg/m² was the only factor associated with suboptimal bowel preparation on both the univariate (P = 0.007) and the multivariate (odds ratio, 1.437; 95% confidence interval, 1.104–1.871; P = 0.007) analyses.

Conclusion

Most lifestyle factors, including dietary patterns, exercise, alcohol intake and smoking, were not associated with suboptimal bowel preparation in Koreans. However, BMI > 25 kg/m² was independently associated with suboptimal bowel preparation. More intense preparation regimens before colonoscopy can be helpful in subjects with BMI > 25 kg/m².

Clear Liquid Versus Low-fibre Diet in Bowel Cleansing for Colonoscopy in Children: A Randomized Trial

OBJECTIVES

In light of a paucity of data on the role of diet in colonoscopy preparation in paediatric population, the present study was designed to compare the effectiveness of clear liquid and low-fibre diets for breakfast and lunch on the day preceding colonoscopy in children.

METHODS

This prospective, randomised trial was conducted at the Department of Paediatric Gastroenterology and Nutrition in Warsaw, Poland. Eligible patients, referred for colonoscopies, were 6 to 18 years old. Patients were randomly divided into 2 groups: the first received a clear liquid diet and the second a low-fibre diet on the day before colonoscopy. In the afternoon, all participants were asked to drink polyethylene glycol with electrolytes at a dose of 66 mL/kg to a maximum of 4 L. The effectiveness of bowel cleansing was measured using the Boston Bowel Preparation Scale (BBPS). The preparation tolerance was assessed by parents and children using a visual analogue scale. Adverse effects were reported.

RESULTS

In total, 184 patients were enrolled. Of those, 96 received the clear liquid diet and 88-the low-fibre diet. The mean age of both groups was 15 years. There were no differences between the 2 study groups in age, weight, and sex, as well as in total BBPS score (BBPS ≥ 5 96.6% vs 95.1%, P = 0.5). The frequency of adverse effects was similar in both groups; nausea was the most common (P = 0.8).

CONCLUSIONS

Clear liquid and low-fibre diets administered to children the day before colonoscopy demonstrated similar bowel cleansing effectiveness.

Comparison of a split-dose bowel preparation with 2 liters of polyethylene glycol plus ascorbic acid and 1 liter of polyethylene glycol plus ascorbic acid and bisacodyl before colonoscopy

BACKGROUND AND AIMS

Recently, a low-volume polyethylene glycol formulation containing ascorbic acid (PEG-Asc) has proven as safe and effective as traditional 4-L PEG solutions for colonoscopy preparation. However, currently available aqueous purgative formulations are poorly tolerated. The aim of this study was to compare a split-dose 2-L PEG-Asc formulation and a 1-L PEG-Asc formulation with bisacodyl (10 mg) to determine the quality of bowel cleansing and patient tolerability.

METHODS

A single-center, randomized, observer-blinded study was performed between May 2015 and September 2015. Two hundred outpatients referred for colonoscopy were prospectively enrolled and assigned to either the split-dose 2-L PEG-Asc group or the 1-L PEG-Asc with bisacodyl 10-mg group. The Boston Bowel Preparation Scale (BBPS) and Aronchick Bowel Preparation Scale (ABPS) were used to evaluate bowel cleansing. The tolerability of the regimens and satisfaction of patients was determined based on a questionnaire.

RESULTS

Two hundred patients received either 2-L PEG-Asc or 1-L PEG-Asc with bisacodyl. Regarding colon cleansing outcome (BBPS and ABPS), the 1-L PEG-Asc with bisacodyl group showed similar but non-inferior results compared with the 2-L PEG-Asc group on both BBPS (6.92 ± 1.63 vs 6.57 ± 1.37; P = .103) and ABPS (96% vs 95%; P = 1.000) scales. Tolerability was similar for both 1-L PEG-Asc with bisacodyl and 2-L PEG-Asc.

CONCLUSIONS

1-L PEG-Asc is a suitable alternative to low-volume bowel preparation for colonoscopy. Our study showed that the 1-L PEG-Asc plus bisacodyl preparation has comparable tolerability and results in adequate colon cleansing. Bowel preparation with bisacodyl and 1-L PEG-Asc is a suitable alternative to low-volume bowel preparation for colonoscopy. (Clinical trial registration number: NCT02980562.).

Controlled Dietary Restriction With a Prepackaged Low-Residue Diet Before Colonoscopy Offers Better-Quality Bowel Cleansing and Allows the Use of a Smaller Volume of Purgatives: A Randomized Multicenter Trial

BACKGROUND

Bowel preparation is burdensome, and less-demanding preparation procedures are needed. Few studies have investigated the effects of low-residue diet and prepackaged low-residue diet in combination with low-volume polyethylene glycol-electrolyte lavage solution during colonoscopy preparation.

OBJECTIVE

We compared self-prepared low-residue diets with prepackaged low-residue diets in combination with low-volume polyethylene glycol.

DESIGN

This was a single-blinded, 3-arm, multicenter, randomized controlled trial.

SETTING

Colonoscopies were conducted in outpatient settings at 3 centers in Taiwan.

PATIENTS

The study included 180 patients (age range, 20-75 years) who were scheduled for colonoscopy.

INTERVENTIONS

Three groups were compared: group A included self-prepared, 1-day, low-residue diets with a same-day 2.0-L single-dose of polyethylene glycol; group B included prepackaged low-residue diets plus 2.0 L of polyethylene glycol; and group C included prepackaged low-residue diets plus 1.5 L of polyethylene glycol.

MAIN OUTCOME MEASURES

The outcome measures were adherence, bowel-cleansing level, and patient satisfaction.

RESULTS

One third of the subjects in group A, but none in the prepackaged low-residue diets groups, violated the dietary restrictions. The proportion of right-segment preparation failure was 15.0%, 1.7%, and 6.7% (p = 0.025). Accordingly, treatment B was superior to A (p = 0.008). Among subjects violating the low-residue diets guideline, the right-segment preparation failure rate was 25%. According to a multivariate analysis, low-residue diet compliance (adjusted OR = 6.55 (95% CI, 1.83-23.43)) and BMI were predictors of right-sided preparation adequacy, but the volume of polyethylene glycol ingested was not a predictor. Compared with group A, a greater proportion of subjects in groups B and C reported satisfaction.

LIMITATIONS

Patients with high BMI and severe constipation were excluded from this study. This study included only an Asian population.

CONCLUSIONS

The prepackaged low-residue diet provides excellent adherence, better bowel cleansing, and a better experience than a self-prepared low-residue diet. With good dietary compliance, 1.5 L of polyethylene glycol provides effective preparation.

Constipation, fiber intake and non-compliance contribute to inadequate colonoscopy bowel preparation: a prospective cohort study

OBJECTIVE

Adequate bowel preparation is important for colonoscopy. Currently available evidence on the determinants of poor bowel preparation is largely derived from studies in Western countries. We aimed to identify the risk factors for inadequate bowel preparation for colonoscopy in the Chinese population.

METHODS

In this single-center study, patients admitted to the Outpatient Department between March 2013 and December 2015 and had indications for colonoscopy were prospectively enrolled. Questionnaires were administered to the patients. Their characteristics and procedure-related parameters such as procedure time were recorded. Bowel preparation was assessed using Boston bowel preparation scale score.

RESULTS

A total of 409 patients with a mean age of 48.8 ± 12.9 years were enrolled in the study, 60.9% of whom were men. On univariate analysis, poor educational level (P = 0.020), chronic constipation (P = 0.001), taking no physical exercise after medication (P < 0.001), a high-fiber diet during the 24-h period immediately preceding the colonoscopy (P < 0.001), incomplete intake of medication (P < 0.001), the passage of yellow or dark stools before colonoscopy (P < 0.001), waiting time (P = 0.001) and stool frequency after medication (P = 0.048) were significantly associated with inadequate bowel preparation. On multivariate analysis, chronic constipation [odds ratio (OR) 2.05, 95% confidence interval (CI) 1.31-3.23, P = 0.002], incomplete intake of the medication (OR 2.77, 95% CI 1.47-5.21, P = 0.002) and a high-fiber diet within 24 h before colonoscopy (OR 2.15, 95% CI 1.40-3.28, P < 0.001) were independent risk factors for inadequate bowel preparation.

CONCLUSIONS

Chronic constipation, poor compliance with treatment and high-fiber diet were predictors of poor bowel preparation. Patients with these risk factors require more effective strategies for bowel preparation.

Improving of bowel cleansing effect for polyethylene glycol with ascorbic acid using simethicone: A randomized controlled trial

BACKGROUND AND AIM

Low-volume polyethylene glycol with ascorbic acid (PEG-Asc) use is reported to be as safe and effective as traditional 4-L polyethylene glycol use. However, PEG-Asc produces bubbles, which cause problems during colonoscopy. Data on the effects of using antifoaming agents such as simethicone with PEG-Asc are lacking. The aim of this CONSORT-prospective, randomized, observer-blinded, controlled trial is to compare the quality of bowel preparation and compliance between PEG-Asc users and PEG-Asc plus simethicone users.

METHODS

Adult outpatients aged 18 to 80 years undergoing colonoscopy were recruited to the study. Two hundred sixty patients were randomly assigned to 1 of 2 treatment arms, PEG-Asc or PEG-Asc plus simethicone. The primary outcome measure was the bowel cleansing quality using Boston bowel preparation scale and bubble scores. The secondary outcome measures were patient tolerability and doctor tolerability.

RESULTS

The simethicone group showed superior cleansing results (6-9 Boston scale scores: 99% vs. 84%, <5% bubble scores: 96% vs. 49%, P < 0.001) and fewer gastrointestinal symptoms (abdominal fullness: 24% vs. 55%, colicky pain: 5% vs. 24%, P < 0.001) than the non-simethicone group. Moreover, endoscopist fatigue during colonoscopy was lower in the simethicone group than in the non-simethicone group (1.31 ± 0.75 vs. 2.97 ± 2.14, P < 0.001).

CONCLUSION

PEG-Asc plus simethicone use was more effective and associated with better patient and endoscopist tolerance than PEG-Asc use. Therefore, this combination is recommended as one of the promising methods for bowel preparation before colonoscopy.

Optimizing bowel preparation for colonoscopy: a guide to enhance quality of visualization

Colonoscopy is an important screening and therapeutic modality for colorectal cancer. Unlike other screening tests, colonoscopy is dependent on pre-procedure bowel preparation. If the bowel preparation is poor, significant pathology may be missed. Many factors are known to improve bowel preparation. This review will highlight those factors that may optimize the bowel preparation, including choice of bowel preparation, grading or scoring of the bowel preparation, special factors that influence preparation, and diet prior to colonoscopy that affects bowel preparation. The aim of the review is to offer suggestions and guide endoscopists on how to optimize the bowel preparation for the patients undergoing colonoscopy.

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.

A randomized controlled trial comparing a prepackaged low-residue diet with a restricted diet for colonoscopy preparation: the impact on the results of colonoscopy in adenoma detection

AIM

This study aimed to investigate the clinical utility of a prepackaged low-residue diet (PLD) compared with a restricted diet (RD) for colonoscopic bowel preparation.

METHOD

A prospective randomized controlled trial was carried out with patients undergoing colonoscopy. One hundred patients were randomly assigned to PLD and RD groups. In the RD group, the patients received an information sheet containing acceptable low-residue options and instructions from the medical staff. All patients received 10 ml sodium picosulphate the day before colonoscopy and 1 l of polyethylene glycol with ascorbic acid (PEG-A) on the day of the colonoscopy. If the bowel preparation was not adequate, an additional PEG-A solution was given. The primary outcome was the efficacy of colonic cleansing as rated by the Boston Bowel Preparation Scale (BBPS). The additional amount of PEG-A solution, adenoma detection rate and patient tolerance were assessed as secondary outcomes.

RESULTS

The BBPS score in the PLD group was 7.3 ± 1.7 compared with 6.5 ± 1.7 in the RD group. The quality of bowel preparation was significantly better in the PLD group (P < 0.05). The mean amount of additional PEG-A solution in the PLD group was smaller than in the RD group (293.8 ± 474.8 vs 444.1 ± 625.0 ml), but there was no statistical difference between the two groups. Adenoma detection rates and patient tolerance were similar in the two groups.

CONCLUSION

Prepackaged low-residue diets PLD is superior to RD for bowel preparation for colonoscopy.

Regime for Bowel Preparation in Patients Scheduled to Colonoscopy: Low-Residue Diet or Clear Liquid Diet? Evidence From Systematic Review With Power Analysis

Clear liquid diet (CLD) is used to perform bowel preparation before colonoscopy traditionally, but several clinical studies indicated that low-residue diet (LRD) generates equal effects to CLD and a conclusive conclusion has not yet been yielded. The systematic review was performed to address this conflict and facilitate informed decision-making eventually. To capture randomized controlled trials (RCTs) comparing LRD with CLD in terms of bowel preparation, a search was performed in PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Science Direct, recent conference abstracts, Google Scholar, and Clinicaltrials.gov through May 2015. We performed all meta-analyses based on fixed- or random-effects model, which is generated from clinical characteristics and methodology. Moreover, the G*Power software was adopted to achieve statistical power for each outcome. In total, we captured 109 potential citations at initial search stage and 2 topic-related articles were included through other sources. After critical appraisal, 7 RCTs were eligible for our inclusion criteria. Meta-analyses generated similar effects in bowel preparation quality, efficacy of colon cleansing, and compliance with recommended dietary regime when LRD versus CLD regime, but patients who were prescribed to receive LRD have slightly better tolerance (RR, 1.06; 95% CI, 1.02-1.11) and tended to repeat the same preparation regime in future (RR, 1.17; 95% CI, 1.09-1.26) relative to patients in CLD. Importantly, both regimes resulted in similar adverse events (AEs). With the best available evidence, LRD could be recommended to be as standard regime for bowel preparation prior to colonoscopy.

Low-residue and low-fiber diets in gastrointestinal disease management

Recently, low-residue diets were removed from the American Academy of Nutrition and Dietetics' Nutrition Care Manual due to the lack of a scientifically accepted quantitative definition and the unavailability of a method to estimate the amount of food residue produced. This narrative review focuses on defining the similarities and/or discrepancies between low-residue and low-fiber diets and on the diagnostic and therapeutic values of these diets in gastrointestinal disease management. Diagnostically, a low-fiber/low-residue diet is used in bowel preparation. A bowel preparation is a cleansing of the intestines of fecal matter and secretions conducted before a diagnostic procedure. Therapeutically, a low-fiber/low-residue diet is part of the treatment of acute relapses in different bowel diseases. The available evidence on low-residue and low-fiber diets is summarized. The main findings showed that within human disease research, the terms "low residue" and "low fiber" are used interchangeably, and information related to the quantity of residue in the diet usually refers to the amount of fiber. Low-fiber/low-residue diets are further explored in both diagnostic and therapeutic situations. On the basis of this literature review, the authors suggest redefining a low-residue diet as a low-fiber diet and to quantitatively define a low-fiber diet as a diet with a maximum of 10 g fiber/d. A low-fiber diet instead of a low-residue diet is recommended as a diagnostic value or as specific therapy for gastrointestinal conditions.

Low-residue breakfast during the preparation for colonoscopy using a polyethylene glycol electrolyte solution: a randomised non-inferiority trial

Goals

To test the hypothesis that the use of a low-residue breakfast (LRB) the day prior to colonoscopy was not inferior to consuming clear fluids alone (CFD) in patients undergoing outpatient colonoscopy with a polyethylene glycol (PEG) bowel preparation.

Background

Optimal colon cleansing is essential for complete visualisation of the mucosa during colonoscopy. Few studies have examined the effect of diet on the quality of bowel cleansing or tolerance in patients using a PEG bowel preparation for colonoscopy.

Methods

Randomised, single-blinded non-inferiority trial. Adult patients scheduled for outpatient colonoscopy with PEG solution were randomised to an LRB followed by clear fluids or CFD using either a traditional or split-dose PEG solution for bowel preparation. The primary outcome was colon cleansing based on the Ottawa Bowel Preparation Score (OBPS).

Results

On an intention-to-treat (ITT) basis, a total of 109 and 105 patients were included in the CFD and LRB arms, respectively, with 116 and 98 patients, respectively, for the per-protocol (PP) analysis. Although there was no difference in the mean total OBPS between the CFD or LRB arms in either the ITT or PP analysis, the threshold for non-inferiority was not met. Patient acceptance of the regimens was higher in the LRB arm than in the CFD arm in the ITT and PP analyses.

Conclusions

This study failed to show the non-inferiority of an LRB in patients receiving bowel preparation with a PEG-based solution. A CFD should be prescribed when using a PEG bowel preparation.

Trial registration number

This trial is registered at ClinicalTrials.gov (NCT01454388).

Optimizing bowel cleansing for colonoscopy

Adequate bowel cleansing is essential for complete examination of the colon mucosa during colonoscopy. Suboptimal bowel preparation has potential adverse consequences, such as missed pathologic abnormalities, the need for repeated procedures, and increased procedure-related complications. Several factors can predict individuals at increased risk for inadequate bowel preparation. If predictors of inadequate bowel preparation are identified, then education should be intensified and a more aggressive bowel regimen recommended. On completion of this article, you should be able to (1) define the frequency of inadequate colon preparations, (2) identify predictors of poor bowel preparation, and (3) use a more aggressive bowel regimen when clinically indicated.

A randomized, prospective trial on efficacy and tolerability of low-volume bowel preparation methods for colonoscopy

BACKGROUND

Low-volume bowel preparations have been shown to provide an equivalent cleansing effect as that of a standard 4 L polyethylene glycol. However, studies comparing the efficacy of low-volume bowel preparations are few, and the results have been controversial. This study aimed to compare the bowel cleansing quality and tolerability between sodium picosulfate/magnesium citrate and polyethylene glycol with ascorbic acid.

METHODS

A randomized study was performed with two hundred outpatients who were prospectively enrolled. The Boston Bowel Preparation Scale and the Aronchick scale were used to evaluate the bowel cleansing quality, and bubble scoring was also performed to back up both results. To investigate patients' preferences and tolerability, a questionnaire was administered.

RESULTS

Sodium picosulfate/magnesium citrate was not inferior to polyethylene glycol with ascorbic acid in terms of successful bowel preparation (≥ 6 Boston scale score: 80% vs. 82%; p = 0.718, adequate Aronchick grade: 93% vs. 96%; p = 0.352). In addition, sodium picosulfate/magnesium citrate caused fewer gastrointestinal symptoms, and tasted better than polyethylene glycol with ascorbic acid.

CONCLUSIONS

Sodium picosulfate/magnesium citrate was not inferior to polyethylene glycol with ascorbic acid in cleansing efficacy, and was found to have higher tolerability.

3-L split-dose is superior to 2-L polyethylene glycol in bowel cleansing in Chinese population: a multicenter randomized, controlled trial

Large volume (4 L) of polyethylene glycol (PEG) solution would ensure a better quality of bowel cleansing but might be poorly tolerated. Due to the smaller body size, lower body weight, and different diet habits, the large volume of 4-L PEG might be poorly tolerated by the Chinese population. In view of this, a balance should be made between the volume and effectiveness. This study aimed to compare the effectiveness, compliance, and safety between 3-L split-dose and 2-L PEG in Chinese population. Consecutive patients scheduled for colonoscopy were recruited from 5 tertiary medical centers in South China between April and July, 2014. Patients were prospectively randomized into 2 groups: 3-L split-dose PEG (3L-group) and 2 L PEG (2L-group). The primary endpoint was bowel cleansing and was defined according to Ottawa Bowel Preparation Scale (OBPS). The safety and compliance were also evaluated. A total of 318 patients were included in the analysis. The mean total OBPS score was significantly higher in 2L-group than in 3L-group (4.4 ± 2.7 vs 2.9 ± 2.4, P < 0.001). Both the intention-to-treat and per-protocol analysis found that rates of successful and excellent bowel preparation were much higher in 3L-group (89.9% and 78.0%) than 2L-group (79.2% and 48.4%), respectively (P < 0.001). The average cecum intubation time was significantly shorter in 3L-group (8.2 ± 3.7 min) than in 2L-group (10.3 ± 4.2 min) (P = 0.04). Adenoma detection rate in right colon was slightly higher in 3L-group than in 2L-group (17.6% vs 12.6%, P = 0.21). The safety and compliance including the taste, smell, and dosage of PEG were similar between 2 groups (P > 0.05). 3-L split-dose PEG is superior to 2-L PEG by better bowel cleansing, improved safety and compliance, shorter cecum intubation time, and potentially higher adenoma detection rate in rightward colon in Chinese population.

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.

Achieving the best bowel preparation for colonoscopy

Bowel preparation is a core issue in colonoscopy, as it is closely related to the quality of the procedure. Patients often find that bowel preparation is the most unpleasant part of the examination. It is widely accepted that the quality of cleansing must be excellent to facilitate detecting neoplastic lesions. In spite of its importance and potential implications, until recently, bowel preparation has not been the subject of much study. The most commonly used agents are high-volume polyethylene glycol (PEG) electrolyte solution and sodium phosphate. There has been some confusion, even in published meta-analyses, regarding which of the two agents provides better cleansing. It is clear now that both PEG and sodium phosphate are effective when administered with proper timing. Consequently, the timing of administration is recognized as one of the central factors to the quality of cleansing. The bowel preparation agent should be administered, at least in part, a few hours in advance of the colonoscopy. Several low volume agents are available, and either new or modified schedules with PEG that usually improve tolerance. Certain adjuvants can also be used to reduce the volume of PEG, or to improve the efficacy of other agents. Other factors apart from the choice of agent can improve the quality of bowel cleansing. For instance, the effect of diet before colonoscopy has not been completely clarified, but an exclusively liquid diet is probably not required, and a low-fiber diet may be preferable because it improves patient satisfaction and the quality of the procedure. Some patients, such as diabetics and persons with heart or kidney disease, require modified procedures and certain precautions. Bowel preparation for pediatric patients is also reviewed here. In such cases, PEG remains the most commonly used agent. As detecting neoplasia is not the main objective with these patients, less intensive preparation may suffice. Special considerations must be made for patients with inflammatory bowel disease, including safety and diagnostic issues, so that the most adequate agent is chosen. Identifying neoplasia is one of the main objectives of colonoscopy with these patients, and the target lesions are often almost invisible with white light endoscopy. Therefore excellent quality preparation is required to find these lesions and to apply advanced methods such as chromoendoscopy. Bowel preparation for patients with lower gastrointestinal bleeding represents a challenge, and the strategies available are also reviewed here.

A randomized controlled trial comparing a low-residue diet versus clear liquids for colonoscopy preparation: impact on tolerance, procedure time, and adenoma detection rate

OBJECTIVE

To achieve an excellent bowel preparation, it is routine to require a clear liquid diet on the day before the procedure. Unfortunately, this dietary modification may be poorly tolerated. We examine whether a change in precolonoscopy dietary restriction can lead to better patient tolerance without compromising examination quality.

METHODS

This is a prospective, blinded, randomized controlled trial of patients undergoing screening or surveillance colonoscopy. The primary objective measures the effect of dietary modification on bowel prep quality. Secondary endpoints include polyp detection, patient tolerance, withdrawal time, and patient acceptance. A total of 200 patients were randomized to either (a) a low-residue diet for breakfast and lunch the day before the procedure or (b) clear liquids all day before the procedure. All patients underwent an identical low-volume sodium sulfate split prep. Bowel prep quality was scored using the Boston Bowel Preparation Scale (BBPS). A t test with TOST was used for noninferiority. Secondary endpoints were compared using χ analysis.

RESULTS

Overall, 96.5% of patients had a good or excellent bowel prep (BBPS=6, 7, 8, or 9). LRD prep quality was noninferior to CLD prep quality (LRD 7.8 vs. CLD 8.1). Polyp detection rates were similar (68% vs. 65.4%, P=0.6899). Patient tolerance and acceptance did not differ. Withdrawal times were equivalent between both groups (16.2 vs. 16.5 min, P=NS).

CONCLUSIONS

Patients allowed to have a limited low-residue diet before colonoscopy achieve a bowel prep quality that is noninferior to patients on a strict clear liquid diet limitation. Furthermore, polyp detection rates, patient tolerance, and patient acceptance were similar between the 2 groups.

A randomized, endoscopist-blinded, prospective trial to compare the preference and efficacy of four bowel-cleansing regimens for colonoscopy

OBJECTIVES

The superiority of conventional polyethylene glycol (PEG) solution over sodium picosulfate with magnesium citrate (SPMC) for bowel preparation remains controversial. Therefore, this study compared the efficacy, safety, and tolerability of different regimens of SPMC and PEG solution in Koreans, who consume a traditional high-fiber diet.

MATERIALS AND METHODS

A total of 200 outpatients undergoing elective colonoscopy were randomized into four groups receiving different bowel-preparation regimens in a prospective study: 4 L PEG in the morning on the day of colonoscopy, two 2 L split doses of PEG, split doses of 2 SPMC sachets, and split doses of 3 SPMC sachets. Bowel cleansing efficacy was assessed based on the Ottawa bowel preparation scale and the Aronchick scale by endoscopists blinded to treatment, and patients filled out a questionnaire to determine satisfaction.

RESULTS

There was no difference among groups with respect to bowel cleansing grade (Ottawa scale, p = 0.314). Patients in the SPMC groups were less likely to have abdominal fullness, pain, nausea, or vomiting than patients in the PEG groups (p < 0.05). Patients reported SPMC was more palatable than PEG. There were no significant differences among groups with respect to polyp detection rate.

CONCLUSION

SPMC is as effective as conventional high-volume PEG-electrolyte solution in Korean patients. SPMC groups reported superior palatability and tolerability compared to PEG groups.

Optimal bowel preparation--a practical guide for clinicians

High-quality bowel preparation is essential for effective colonoscopy. Bowel preparations are judged by their safety, efficacy and tolerability. Between efficacy and tolerability, efficacy is the clinical priority because inadequate preparations are disruptive and costly. Achieving high rates of adequate preparation depends first on using split-dose or same-day dosing. Patients who have medical predictors of inadequate preparation quality (for example chronic constipation) should be prescribed more aggressive preparations and patients who have factors that predict they are less likely to follow the instructions (such as English not being their first language) should receive intensified education. On the day of the procedure, patients with persistent brown effluent should be considered for large-volume enemas or additional oral preparation before proceeding with colonoscopy. During the procedure, preparation quality should be graded after the clean-up has been completed.

Quality bowel preparation for surveillance colonoscopy in patients with inflammatory bowel disease is a must

Colonoscopy is routinely performed in patients with inflammatory bowel disease (IBD) for surveillance of dysplasia. Thorough bowel preparation is necessary to facilitate lesion detection. Patients with IBD do not have poorer bowel preparation outcomes but may have decreased preparation tolerance affecting adherence to surveillance protocols. A low-fiber prepreparation diet may improve preparation tolerance without affecting preparation quality. The standard preparation regimen should consist of split-dose administration of a polyethylene glycol-based purgative. Low-volume, hyperosmolar purgatives may be considered in patients with previous preparation intolerance, heightened anxiety, stenotic disease, or dysmotility. Appropriate patient education is critical to enhance preparation quality.

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

BACKGROUND/AIMS

Split-dose polyethylene glycol (PEG) is a standard bowel preparation regimen for colonoscopy, but the large volume is burdensome to ingest and the night dose causes sleep disturbance. This study was performed to evaluate the efficacy and tolerability of a bowel preparation protocol using low-volume morning-only PEG with specially designed low-residue test meals (LV-PEG with TM) compared to a standard-volume split-dose PEG bowel preparation with a standard diet (SV-PEG with SD).

METHODS

This was a single-center, prospective, randomized, investigator-blinded, noninferiority study. The primary end point was bowel preparation quality according to the Ottawa scale. Tolerability, compliance, adverse events, sleep quality and polyp/adenoma detection were also assessed.

RESULTS

Among 197 patients analyzed (mean age 54.6 years, 51.3% men), 97 received LV-PEG with TM and 100 received SV-PEG with SD. The Ottawa score for the total colon was 3.76 ± 2.07 in the LV-PEG with TM group and 3.67 ± 1.57 in the SV-PEG with SD group (p = 0.723; difference 0.09, 95% confidence interval -0.60 to 0.42). The compliance was high (more than 95%) in both groups (p = 0.621). PEG was easier to ingest for patients in the LV-PEG with TM group compared to the SV-PEG with SD group [visual analogue scale (VAS) for difficulty: 4.64 ± 2.46 vs. 5.97 ± 2.42, respectively; p < 0.001]. Diet instructions were also easier to comply with for patients in the LV-PEG with TM group compared to the SV-PEG with SD group (VAS for difficulty: 3.11 ± 2.25 vs. 4.00 ± 2.39, respectively; p = 0.008). Patients in the LV-PEG with TM group had a lower incidence of abdominal bloating (p = 0.012) and better sleep quality (p < 0.001). There was no difference between the groups regarding polyp and adenoma detection.

CONCLUSIONS

LV-PEG with TM and SV-PEG with SD have similar efficacy with regard to bowel preparation for colonoscopy. LV-PEG with TM provided easier PEG intake and diet compliance, less abdominal bloating and better sleep quality than SV-PEG with SD.

Can nutritional supplements and rectal enema be used as bowel cleansing for colonoscopy?--Results of a randomized controlled pilot study

OBJECTIVE

Currently available preparations for colonoscopy have low tolerability and may cause fluid and electrolyte shifts. An alternative method of bowel cleansing is required.

MATERIAL AND METHODS

Preparation of the gut using oral nutritional supplements (ONS) and rectal enema was tested as an alternative method of bowel cleansing. During 2008-2012, patients were randomized to oral nutritional supplements (n = 27) for 5 days and rectal enema or polyethylene glycol (PEG) (n = 23) prior to colonoscopy. Blinded endoscopists rated the degree of bowel cleansing according to the Ottawa bowel preparation scale (OBS) (primary outcome). Tolerability of either preparation was also assessed

RESULTS

Due to a high rate of bowel cleansing failure among patients receiving ONS, the study was interrupted prematurely. Colonoscopies were incomplete due to stools in 6 of 27 patients in the ONS group compared to 1 of 23 in the PEG group (ns). The mean total OBS were 8.3 ± 3.3 and 5.3 ± 2.8, respectively (p = 0.002). Four patients (15%) in the ONS group and eight patients (35%) receiving PEG had an OBS score ≤4 (good preparation) (ns). ONS was better tolerated than PEG with more patients reporting acceptable taste (27 of 27 [100%] vs. 15 of 23 [65%], p = 0.001), and fewer reporting difficulties with the intake (0 of 27 [0%] vs. 10 of 23 [43%], p < 0.001) and nausea (5 of 27 [19%] vs. 13 of 23 [57%], p < 0.008).

CONCLUSIONS

For routine use, ONS with enema instead of traditional preparation for colonoscopy with PEG cannot be generally recommended.

Randomized clinical trial comparing reduced-volume oral picosulfate and a prepackaged low-residue diet with 4-liter PEG solution for bowel preparation

BACKGROUND

Reduced-volume bowel preparation with a low-residue diet prior to colonoscopy would result in better patient compliance and sufficient bowel preparation.

OBJECTIVE

To compare the clinical efficacy of reduced-volume sodium picosulfate and a prepackaged low-residue diet with that of the standard bowel preparation using 4 L of PEG solution.

DESIGN

Prospective, single center, single blind, active control, randomized study (NCCCTS-12-619, KCT0000470).

SETTING

Ambulatory outpatient clinic at the National Cancer Center, Republic of Korea.

PATIENTS

A total of 194 subjects were randomly assigned for this study, 97 in each group. After exclusions, 94 subjects in the Picolight group and 90 in the PEG group completed the study and were analyzed.

INTERVENTIONS

Sodium picosulfate with a prepackaged low-residue, one-day diet or 4-L PEG for bowel preparation.

MAIN OUTCOME MEASURES

Success rate of the bowel preparation, tolerability, adverse events, cecal intubation time, polyp detection rate and adenoma detection rate.

RESULTS

The bowel preparation success rate was significantly higher (91.5% vs. 81.1%, p = 0.04) and the rates of adverse events, including abdominal distension, pain, nausea, vomiting and abdominal discomfort, were significantly lower in the picosulfate group than the PEG group. Cecal intubation times and the polyp and adenoma detection rates were similar in the 2 groups.

LIMITATIONS

Single center, limited population, all colonoscopies were performed in the morning.

CONCLUSIONS

Bowel preparation with low-volume oral picosulfate and a prepackaged low-residue diet enhances colon cleansing and is better tolerated than the standard bowel preparation.

The modern bowel preparation in colonoscopy

Adequate bowel preparation is essential for optimal colonoscopy. Suboptimal bowel preparation occurs in 25% to 40% of cases and is associated with canceled procedures, prolonged procedure time, incomplete examination, increased cost, and missed pathology. There are several effective formulations for colon cleansing with a good safety profile. Split dosing should be implemented whenever possible in an effort to enhance tolerance and adherence, and improve mucosal visibility and overall quality of the examination. In this review, modern bowel preparations are discussed including their mechanism of action, mode of use, safety, and how to optimize outcomes.

A clear liquid diet is not mandatory for polyethylene glycol-based bowel preparation for afternoon colonoscopy in healthy outpatients

Background/Aims

A dietary regimen consisting of a clear liquid diet (CLD) for at least 24 hours is recommended for colonoscopy preparation. However, this requirement results in problems in patient compliance with bowel preparation. The aim of this study was to evaluate the efficacy of a CLD compared with a regular diet (RD) for colonoscopy preparation using a polyethylene glycol (PEG) solution.

Methods

This was a multicenter, randomized, investigator-blind prospective study. A total of 801 healthy outpatients undergoing afternoon colonoscopy were randomized to either a CLD or RD in addition to a 4 L PEG regimen.

Results

The quality of bowel cleansing was not different between the CLD and RD groups in terms of the proportion with excellent or good preparation. In addition, no significant differences were observed between the two groups for polyp and adenoma detection rates and overall adverse events. Good compliance with bowel preparation was higher in the RD group than in the CLD group.

Conclusions

A CLD for a full day prior to colonoscopy should not be mandatory for PEG-based bowel preparation. Dietary education concerning the avoidance of high-fiber foods for 3 days before colonoscopy is sufficient, at least for healthy outpatients.