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

Comparison of the effect of 1-day and 2-day low residue diets on the quality of bowel preparation before colonoscopy

BACKGROUND/AIM

Low residue diet (LRD) has a similar quality of bowel preparation with clear liquid diet before colonoscopy, but improved patient tolerance. However, the optimal LRD duration is still controversial. In this study, we have compared the effect of a 1-day LRD and 2-day LRD on the quality of bowel preparation and patient tolerance.

PATIENTS AND METHODS

Our prospective, randomized, single-blind trial, single-blind, trial compared two dietary regimens administered the day before colonoscopy. All patients were administered PEG-ES and simethicone for bowel preparation. The primary outcome measure was bowel preparation quality. The secondary outcome measures were insertion time, withdrawal time, polyp detection rate, patient tolerance, and willingness to use the same diet for bowel preparation again. Bowel preparation quality was evaluated using the Boston bowel preparation scale (BBPS). Patient tolerance was evaluated using a hunger-comfort scale.

RESULTS

There was no significant difference in bowel preparation quality between the 2 groups. The 1-day LRD group had a BBPS score of 6.48 ± 1.59 points, while the 2-day LRD group had a score of 6.42 ± 1.06 points (P > 0.05). The groups reported similar colonoscope insertion times, withdrawal times, polyp detection rates and patient tolerance scores (hunger-comfort scores). The numbers of patients who reported that compliance as easy or very easy were 126 (78.2%) in the 1-day group versus 88 (55.0%) in the 2 day group (P < 0.05) and the numbers who were willing to use the diet again in the future were 154 (95.7%) in the 1-day group versus 131 (81.9%) in the 2 day group (P < 0.05).

CONCLUSION

LRD duration (1 day or 2 days) had no significant effect on bowel preparation quality. Patients in the 1-day LRD group had higher tolerance and satisfaction levels than patients in the 2-day LRD group. However, overall satisfaction was higher with the 1-day LRD group than with the 2-day LRD group.

Risk Factors Associated with Inadequate Bowel Preparation in Patients with Functional Constipation

BACKGROUND

Constipation is a common reason of poor bowel preparation, which negatively influences the quality of colonoscopy. Risk factors for inadequate bowel preparation in constipated patients remain unclear.

AIMS

This study aimed to investigate the high-risk factors that might influence the quality of bowel preparation in patients with functional constipation.

METHODS

Consecutive patients with functional constipation who underwent colonoscopy between June 2016 and April 2017 were enrolled. A standard split dose of 4 l polyethylene glycol was used for bowel preparation. Patient- and procedure-related parameters were recorded. The primary outcome was an adequate rate of bowel preparation. Risk factors for inadequate bowel preparation were screened by multivariate logistic regression analysis.

RESULTS

A total of 199 patients were included. Adequate bowel preparation was found in 62.8% (125/199) of patients. At multivariate analysis, Bristol stool form scale (BSFS) 1 [odds ratio (OR) 2.73, 95% confidence interval (CI) 1.26-5.90; P = 0.011], rectal pain score during defecation < 2 (OR 4.14, 95% CI 1.22-13.97; P = 0.022), and starting-to-defecation interval ≥ 4 h (OR 3.83, 95% CI 1.34-10.91; P = 0.012) were risk factors for inadequate bowel preparation in patients with constipation. For patients with no, 1, 2, or 3 risk factors, the rates of inadequate bowel preparation were 11%, 23%, 49%, and 65%, respectively.

CONCLUSIONS

With the standard preparation regime, > 1/3 of patients with functional constipation had inadequate bowel cleansing. BSFS 1, rectal pain score during defecation < 2, and starting-to-defecation interval ≥ 4 h were identified as independent risk factors for inadequate bowel preparation in constipated patients.

TRIAL REGISTRATION

ClinicalTrials.gov number NCT02842411.

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.

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.

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.

The impact of diet liberalization on bowel preparation for colonoscopy

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

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

Background/Aims

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

Methods

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

Results

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

Conclusions

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

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.

Advances in bowel preparation for colonoscopy

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

[Bowel preparation for colonoscopy. Any significant progress on the horizon?]

Colonoscopy is the method of choice for colorectal cancer screening. To be effective, screening colonoscopy must have high quality standards. The key element is the quality of the preparation. However, up to 20% of patients are inadequately prepared and, at present, anterograde washing is the least tolerated part of the procedure. In the choice of preparation, safety is a prerequisite and efficacy is a priority. Tolerance is a secondary but nevertheless influential factor in the quality of preparation and has consequently been the primary focus of many recent studies. In the last few years, a rapidly increasing number of studies have evaluated new drugs, dosages and adjuvant therapies to improve efficacy and tolerability. These studies have collaterally shown that inadequate preparation and lack of adherence to the prescribed regimen can be partially predicted, making it essential to identify this patient subgroup and invest the necessary effort in their instruction. New individualized and flexible approaches are expected for the different clinical scenarios. The search for the ideal colonoscopy preparation, which would be tolerable, safe and above all effective, remains open.

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.