Bowel preparation prior to colonoscopy: A continual search for excellence

Dried lemon slices improve bowel cleansing quality of polyethylene glycol for colonoscopy preparation: randomized controlled trial

BACKGROUND

adequate bowel preparation is related to the quality of colonoscopy. Dried lemon slices can increase gastrointestinal peristalsis, which has shown potential as an adjuvant of bowel preparation. We hypothesized that the combination of dried lemon slices and polyethylene glycol (PEG) could improve the efficacy of bowel preparation and be more acceptable to participants.

AIM

to investigate the effectiveness of lemon slices combined with PEG for colonoscopy preparation.

METHODS

a prospective, single-center, randomized, controlled trial was performed of 521 patients randomly assigned to two groups. A total of 254 patients were given lemon slices based on conventional 4-L PEG treatment for the bowel, while 267 patients received only 4-L PEG treatment. Patients' basic information, procedure-related parameters, adverse effects, and subjective feelings were collected by questionnaires. Intestinal tract cleanliness was scored according to the Boston Bowel Preparation Scale (BBPS) by experienced endoscopists. Data were analyzed by the two-sample t-test or the Chi-squared test.

RESULTS

the BBPS scores were significantly higher in the PEG + lemon slice group (p < 0.05). The taste acceptability, satisfaction, and willingness to repeat bowel preparation were significantly higher in the PEG+ lemon slice group (p < 0.05). However, a larger proportion of patients from the PEG+ lemon slice group (30.7 %) suffered abdominal distension compared with the PEG group (20.6 %), while the incidence of other adverse effects was comparable between the two groups.

CONCLUSION

the addition of dried lemon slices to conventional PEG showed its superiority for bowel preparation.

Sodium picosulfate/magnesium citrate versus 4L split-dose polyethylene glycol for bowel cleansing prior to colonoscopy in high fibre diet African patients

Introduction

an adequate bowel preparation is essential for good mucosal inspection during colonoscopy. This study aims to compare the efficacy of two validated oral lavage solutions for colonoscopy preparation in African patients.

Methods

a prospective observational study of patients undergoing colonoscopy in a referral endoscopy facility in Port Harcourt, Nigeria, using sodium picosulfate magnesium citrate (SPMC) and 4L split-dose polyethylene glycol (PEG). Variables collated were sociodemographic, primary indication, comorbidities, Aronchick bowel preparation scale, polyp/adenoma detection, caecal intubation and outcome. Statistical analysis was performed using IBM SPSS version 20.

Results

one hundred and twenty-four patients received PEG prior to colonoscopy and SPMC in 175 patients. The age range was from 22 to 92 years; mean age of 53.8 ± 14.2 years for PEG group and 55.3 ± 13.2 years for SPMC group (p=0.361). There were 215 males and 84 females. An excellent/good bowel preparation scale was recorded in 77 (62%) PEG group and 130 (74.3%) for SPMC group (p=0.592). PEG was predominantly used in the early years of endoscopists practice with the odds ratio (OR) of no polyp detection in the PEG vs SPMC groups as 1.64 (confidence interval CI 1.06-2.55) versus 0.76 (CI 0.62-0.92), respectively (p=0.016). For no adenoma detection, OR was 4.18 (CI 1.12-15.60) versus OR 0.63 (CI 0.52-0.75), respectively (p=0.012).

Conclusion

there is similar efficacy profile using either split volume PEG or SPMC prior to colonoscopy in these African patients. Polyp and adenoma detection rates are highly dependent on the expertise of the endoscopist.

Combination of bisacodyl suppository and 1 L polyethylene glycol plus ascorbic acid is a non-inferior and comfortable regimen compared to 2 L polyethylene glycol plus ascorbic acid

BACKGROUND AND AIM

Appropriate bowel cleansing before colonoscopy is an important factor in increasing the detection rate of lesions. Low-volume polyethylene glycol (PEG) plus ascorbic acid (PEG-Asc) reduces the dosage of bowel preparation agent, but still presents discomfort to patients. The primary aim of the present study was to compare the efficacy of bowel cleansing between 2 L PEG-Asc (control) and 1 L PEG-Asc with bisacodyl suppository (suppository) groups, and the secondary aim was to investigate complications and tolerability between the two groups.

METHODS

This was a single-center prospective randomized controlled study. We identified 168 patients scheduled for colonoscopy between August 2017 and January 2018 and randomly assigned them to the control or to the suppository groups. Efficacy of bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS), and side-effects were surveyed using questionnaires.

RESULTS

No significant difference was detected in baseline characteristics including insertion and withdrawal times, and adenoma detection rates between the two groups. Total BBPS score was 7.93 ± 1.06 and 7.74 ± 1.02 in the control and suppository groups, respectively (P = 0.22). Incidence of abdominal pain and nausea was not statistically different, whereas that of sleep disturbance and anal discomfort was higher in the control group. (P = 0.00).

CONCLUSIONS

One liter PEG-Asc with bisacodyl suppository resulted in an equivalent bowel-cleansing outcome with reduced patient discomfort compared to 2 L PEG-Asc. Therefore, PEG-Asc with bisacodyl suppository represents a potential alternative and increases patient compliance with bowel preparation.

A meta-analysis of randomized controlled trials of the addition of lubiprostone to bowel preparation before colonoscopy

AIM

Adequate bowel preparation is essential to the quality of colonoscopy. We performed a meta-analysis to determine the efficacy and safety of the addition of lubiprostone to the bowel preparation process prior to colonoscopy.

METHODS

Online databases, namely, PubMed, MEDLINE and Cochrane Library, were searched for randomized controlled trials that assessed the additive effect of lubiprostone on the quality of colon preparation in patients undergoing colonoscopy. Each included study was evaluated by the Jadad score to assess the quality of the study. The primary outcome was bowel preparation efficacy, defined as the proportion of patients with an excellent or poor preparation. The secondary outcomes included the length of the colonoscopy, polyp detection, and any adverse effects.

RESULTS

In total, 5 articles published between 2008 and 2016 fulfilled the selection criteria. The addition of lubiprostone to the bowel cleansing process significantly increased the proportion of patients with an excellent preparation (risk ratio [RR] = 1.68, 95% confidence interval (CI): 1.40-2.02, P < .00001) but did not decrease the procedural time or increase the polyp detection rate (mean difference = -0.52, 95% CI: -3.74-2.69, P = .75; RR = 1.16, 95% CI: 0.96-1.42, P = .13, respectively). There was no significant difference in the proportion of patients with any adverse events.

CONCLUSION

The addition of lubiprostone to the bowel preparation regimen prior to colonoscopy is effective and safe.

Comparative efficacy of combination of 1 L polyethylene glycol, castor oil and ascorbic acid versus 2 L polyethylene glycol plus castor oil versus 3 L polyethylene glycol for colon cleansing before colonoscopy: Study protocol of a randomized, double-blind, single-center study

Colonoscopy has been regarded as an important method of early diagnosing and treating gastrointestinal lesions; however adequate bowel preparation is critical one of many factors needed for successful colonoscopy. Although several modified or novel regimes have been developed, desired quality of bowel preparation has not yet been generated. Scattered evidences revealed that castor oil may have potential of effectively cleansing colon. It is noted that, however, prospective trial of exploring the value of castor oil in preparing bowel before colonoscopy is lacking. The aims of this study are to test the hypotheses that low dose castor oil (30 mL) may enhance potential of polyethylene glycol (PEG) and combination of low castor oil and ascorbic acid may halve the volume of PEG.This is a randomized, double-blind (endoscopist and assessor), single center trial with three-arm design. We will randomly assign 282 adult patients (≥18 years but < 75 years), who are scheduled to undergo colonoscopy, to receive either 3 L PEG alone, 2 L PEG plus 30 mL castor oil or combination of 1 L PEG, 30 mL castor oil and 5 g ascorbic acid. The bowel preparation quality based on Boston Bowel Preparation Scale (BBPS) is the primary outcome. The secondary outcomes include the first defecation time, total number of defecation, time of cecal intubation, detection rate of polyp and adenoma, willing to repeat the same regime, tolerance to regime, and adverse events.The study protocol has been approved by the Clinical Research Ethics Committees of Chongqing University Cancer Hospital & Chongqing Cancer Institute & Chongqing Cancer Hospital & Chongqing Cancer Center (2017[107]). The results from this trial will be submitted for publication in peer-reviewed journals, and will be presented at national and international conferences.

Bowel Preparation for a Better Colonoscopy Using Polyethylene Glycol or C-lax: A Double Blind Randomized Clinical Trial

BACKGROUND

Ideal bowel preparation regimen for a suitable colonoscopy should be safe, and well tolerated, and should rapidly clear gastrointestinal tract. Soluble polyethylene glycol (PEG) is the most common cleansing drug and Senna or C-Lax (Cassia angustifolia Vahl) is an alternative herbal one. This study was designed to compare the efficacy of PEG and C-lax in bowel preparation.

METHODS

In this randomized double blind trial (registry number in IRCT.ir: IRCT201601161264N7), 320 patients were randomly assigned in PEG or C-lax groups. PEG solution was prepared from 5×70 gr sachets in 20×250cc water (250 ml every 15 minutes), prescribed 24h before the colonoscopy. In the other group 3×60 ml C-lax syrup glasses (each containing 90 mg senozid B) was given in two divided doses (1.5 glasses of 250cc every 12 hours), 24h before the colonoscopy. Ottawa score was used to evaluate the quality of bowel preparation. Chi-square test, Student t test, MannWhitney test and multivariate analysis were used to analyze the data.

RESULTS

Of these patients with the mean (SD) age of 50 (15.16) years, 162 (50.8%) were men. Mean (SD) Ottawa score was 2.57 (0.2) and 3.15 (0.31) in the PEG and C-lax group, respectively (p value = 0.81). Multivariate analysis showed that less opium consumption (p < 0.001) and higher educational level (p =0.005) were associated with better bowel preparation.

CONCLUSION

C-Lax is non-inferior to PEG solution in cleansing colon. The quality of bowel preparation was lower in opium consumers and better in those with higher educational level.

Cap-assisted colonoscopy versus standard colonoscopy: is the cap beneficial? A meta-analysis of randomized controlled trials

Background:

In an effort to improve visualization during colonoscopy, a transparent plastic cap or hood may be placed on the end of the colonoscope. Cap-assisted colonoscopy (CAC) has been studied and is thought to improve polyp detection. Numerous studies have been conducted comparing pertinent clinical outcomes between CAC and standard colonoscopy (SC) with inconsistent results.

Methods:

Numerous databases were searched in November 2016. Only randomized controlled trials (RCTs) involving adult subjects that compared CAC to SC were included. Outcomes of total colonoscopy time, time to cecum, cecal intubation rate, terminal ileum intubation rate, polyp detection rate (PDR), and adenoma detection rate (ADR) were analyzed in terms of odds ratio (OR) or mean difference (MD) with fixed effect and random effects models.

Results:

Five hundred eighty-nine articles and abstracts were discovered. Of these, 23 RCTs (n=12,947) were included in the analysis. CAC showed statistically significant superiority in total colonoscopy time (MD -1.51 min; 95% confidence interval [CI] -2.67 to -0.34; P<0.01) and time to cecum (MD -0.82 min; 95%CI -1.20 to -0.44; P<0.01) compared to SC. CAC also showed better PDR (OR 1.17; 95%CI 1.06-1.29; P<0.01) but not ADR (OR 1.11; 95%CI 0.95-1.30; P=0.20). In contrast, on sensitivity analysis, ADR was better with CAC. Terminal ileum intubation and cecal intubation rates demonstrated no significant difference between the two groups (P=0.11 and P=0.73, respectively).

Conclusions:

The use of a transparent cap during colonoscopy improves PDR while reducing procedure times. ADR may improve in cap-assisted colonoscopy but further studies are required to confirm this.

A Modified Bowel Preparation Regimen for Colonoscopy Providing the Patients' Satisfaction and Convenience

Background

A complete cleansing of the bowel is a critical factor that impacts the diagnostic accuracy of colonoscopies. However, the common bowel preparation regimen of two 45 mL doses of sodium phosphate (2×NaP) often leads to uncomfortable symptoms and subsequently lower patient adherence. To improve patient adherence and satisfaction, we proposed a modified regimen composed of two sennoside tablets and one bottle of NaP (S+NaP) and we then evaluated bowel preparation quality and patient satisfaction.

Material/Methods

A total of 531 patients who underwent colonoscopies at the outpatient coloproctology clinic from January 2016 to December 2016 were retrospectively reviewed. Eligible patients were divided into two groups: S+NaP group (n=93) and 2×NaP group (n=60). We compared bowel preparation quality, adenoma detection rate (ADR), self-reported patient satisfaction scores, and adverse events among the two groups.

Results

Regarding high bowel preparation quality, our results showed that there was no significant difference among the two groups (p=0.775), as well as no significant differences in ADRs (p=0.187). However, a lower proportion of nausea was found in the S+NaP group compared to the 2×NaP group (24.7% versus 41.7%, respectively, p=0.028). In addition, patients in the S+NaP group were more likely to be very satisfied with the regimen compared with patients in the 2×NaP group (odds ratio: 5.58; 95% confidence interval: 2.36–13.213, p<0.001).

Conclusions

Our modified bowel preparation regimen, S+NaP, yielded significantly higher patient satisfaction with less nausea while maintaining similar bowel preparation quality.

MR colonography with a fecal tagging technique and water-based enema for the assessment of inflammatory bowel disease

PURPOSE

To assess the usefulness of MR colonography (MRC) with a fecal tagging technique and water-based enema in patients with inflammatory bowel disease (IBD).

MATERIALS AND METHODS

Twenty-two patients with suspected or known IBD underwent MRC with a 1.5-T MR system (Siemens Symphony) using a phased-array coil. A fecal tagging technique was performed by oral administration of dense barium sulfate (200 ml) at major meals starting 2 days before the MRI. After a water enema (2000-2500 ml), the MR protocol was carried out, starting with HASTE and true-FISP sequences. Coronal T1w 3D VIBE (2.0 mm thick) was obtained before and 60 s after intravenous administration of Gd chelate. MR images were evaluated by consensus agreement of two observers in terms of image quality and by searching for bowel abnormalities. MRC findings were correlated with our gold standard-conventional colonoscopy (incomplete in 6/22 patients) with histopathological analysis, and surgery (performed in 8/22 subjects).

RESULTS

The MR imaging protocol was completed in all of the investigated subjects. In terms of image quality, 128 out of 132 colon segments (97 %) were considered diagnostic on MR examinations by the two reviewers; signs of bowel inflammation were identified in 74 and 72 % of colon segments of patients with ulcerative colitis (n = 6) and Crohn's disease (n = 15), respectively. In 13/15 patients with Crohn's disease, involvement of both the large and small bowel was demonstrated on MR imaging; perianal abscesses and fistulas were also identified in 2 and 3 of these patients, respectively. In one patient with normal MRC, a diagnosis of IBD could not be confirmed.

CONCLUSION

MRC with a fecal tagging technique and water-based enema is a promising minimally invasive technique for evaluating the bowel in patients with a suspected or established diagnosis of IBD.

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.

Miralax with gatorade for bowel preparation: a meta-analysis of randomized controlled trials

OBJECTIVES

Polyethylene glycol (PEG) is a very popular bowel preparation for colonoscopy. However, its large volume may reduce patient compliance, resulting in suboptimal preparation. Recently, a combination of Miralax and Gatorade has been studied in various randomized controlled trials (RCTs) as a lower volume and more palatable bowel preparation. However, results have varied. Therefore, we conducted a meta-analysis assessing the use of Miralax-Gatorade (M-G) vs. PEG for bowel preparation before colonoscopy.

METHODS

Multiple databases were searched (January 2014). RCTs on adults comparing M-G (238-255 g in 1.9 l that is 64 fl oz) vs. PEG (3.8-4 l) for bowel preparation before colonoscopy were included. The effects were analyzed by calculating pooled estimates of quality of bowel preparation (satisfactory, unsatisfactory, excellent), patient tolerance (nausea, cramping, bloating), and polyp detection by using odds ratio (OR) with fixed- and random-effects models.

RESULTS

Five studies met inclusion criteria (N=1,418), with mean age ranging from 53.8 to 61.3 years. M-G demonstrated statistically significantly fewer satisfactory bowel preparations as compared with PEG (OR 0.65; 95% confidence interval (CI): 0.43-0.98, P=0.04) but more willingness to repeat preparation (OR 7.32; 95% CI: 4.88-10.98, P<0.01). Furthermore, no statistically significant differences in polyp detection (P=0.65) or side effects were apparent between the two preparations for nausea (P=0.71), cramping (P=0.84), or bloating (P=0.50). Subgroup analysis revealed similar results for split-dose M-G vs. split-dose PEG.

CONCLUSIONS

M-G for bowel preparation before colonoscopy was inferior to PEG in bowel preparation quality while demonstrating no significant improvements in adverse effects or polyp detection. Therefore, PEG appears superior to M-G for bowel preparation before colonoscopy.

Factors associated with incomplete colonoscopy at a Japanese academic hospital

AIM: To evaluate significant risk factors for incomplete colonoscopy at a Japanese academic hospital.

METHODS: A total of 11812 consecutive Japanese people were identified who underwent a colonoscopy at an academic hospital. A multiple logistic regression model was used to evaluate retrospectively the significant risk factors for incomplete colonoscopy.

RESULTS: The cecal intubation rate was 95.0%. By univariate analysis, age, female sex, poor bowel cleansing, and a history of abdominal or pelvic surgery were significant risk factors for incomplete colonoscopy (P < 0.001). Moreover, age- and sex-adjusted analysis showed that significant risk factors for incomplete colonoscopy were female sex (OR = 1.38, 95%CI: 1.17-1.64, P = 0.0002), age ≥ 60 years old (OR = 1.44, 95%CI: 1.22-1.71, P < 0.0001), a history of prior abdominal or pelvic surgery (OR = 1.55, 95%CI: 1.28-1.86, P < 0.0001), poor bowel cleansing (OR = 4.64, 95%CI: 3.69-5.84, P < 0.0001), and inflammatory bowel disease (IBD) (OR = 1.48, 95%CI: 1.13-1.95, P = 0.0048). In Japanese men, by age-adjusted analysis, IBD (OR = 1.69, 95%CI: 1.18-2.43, P = 0.005) was an independent risk factor for incomplete colonoscopy.

CONCLUSION: Several characteristics in the Japanese population were identified that could predict technical difficulty with colonoscopy.

What is the best strategy for successful bowel preparation under special conditions?

Adequate bowel preparation is important for successful colonoscopic examination. Several effective colonic cleansing agents are available and routinely prescribed, but each carries its own limitations and benefits from particular dosing regimens. The most frequently prescribed colonic cleansing agent, the polyethylene glycol (PEG) cathartic solution, suffers from low patient compliance in general, due to its unpalatable taste and smell coupled with the large ingested volumes required. However, PEG is preferred over other cathartics for use in individuals of advanced age, sufferers of chronic kidney disease, heart failure and inflammatory bowel disease, and women who are pregnant or lactating. The laxative agents sodium phosphate (NaP) and sodium picosulfate plus magnesium citrate have been applied and have improved patient compliance and tolerance. NaP, however, should be avoided in individuals with impaired renal function or plasma clearance, such as those with chronic kidney disease, who are taking drugs that affect renal function, or who suffer from heart failure. Other special conditions that may affect an individual’s tolerance of the cathartic agent or ability to complete the administration routine include stroke, severe constipation, hematochezia, suspicious lower gastrointestinal bleeding, and mental disorders such as dementia. All ingestible bowel preparation solutions can be instilled into the stomach and duodenum through nasogastric tube or esophagogastroduodenoscope with the aid of a water irrigation pump for patients with difficulties swallowing or ingesting the large volumes of fluid required. In addition, dietary regimens based on clear liquids and low-residue foods for 1-4 d prior to the colonoscopy may be supplemental bowel preparation strategies. Achieving an effective and safe cleansing of the bowel is important for successful colonoscopy in all patients, so full knowledge of the individual’s condition and capabilities is necessary to select the most appropriate colonic cleansing agent and delivery regimen.

Adjuncts to colonic cleansing before colonoscopy

Pre-procedural cleansing of the bowel can maximize the effectiveness and efficiency of colonoscopy. Yet, efficacy of the current gold standard colonic preparation method - high-volume oral administration of purgative agents 12-24 h prior to the procedure - is limited by several factors, such as patient compliance (due to poor palatability and inconvenience of the dosing regimen) and risks of complications (due to drug interactions or intolerance). Attempts to resolve these limitations have included providing adjunctive agents and methods to promote the colonic cleansing ability of the principal purgative agent, with the aim of lessening unpleasant side effects (such as bloating) and reducing the large ingested volume requirement. Several promising adjunctive agents are bisacodyl, magnesium citrate, senna, simethicone, metoclopramide, and prokinetics, and each are being investigated for their potential. This review provides an up to date summary of the reported investigations into the potencies and weaknesses of the key adjuncts currently being applied in clinic as supplements to the traditional bowel preparation agents. While the comparative analysis of these adjuncts showed that no single agent or method has yet achieved the goal of completely overcoming the limitations of the current gold standard preparation method, they at least provide endoscopists with an array of alternatives to help improve the suboptimal efficacy of the main cleansing solutions when used alone. To aid in this clinical endeavor, a subjective grade was assigned to each adjunct to indicate its practical value. In addition, the systematic review of the currently available agents and methods provides insight into the features of each that may be overcome or exploited to create novel drugs and strategies that may become adopted as effective bowel cleansing adjuncts or alternatives.

Role of mosapride in improvement of bowel preparation before colonoscopy in patients with constipation

AIM: To investigate the role of mosapride in improvement of bowel preparation before colonoscopy in patients with constipation.

METHODS: Ninety patients with chronic constipation who requested colonoscopy were randomly and equally divided into three groups: A, B and C. Group A was given polyethylene glycol solution, group B was treated by mosapride plus polyethylene glycol solution, and group C was given mosapride alone. The extent of intestinal cleanliness and the incidence of side effects were compared between the three groups.

RESULTS: The colon cleaning score was significantly higher in groups C and B than in group A (7.13 ± 1.12, 6.65 ± 1.18 vs5.81 ± 1.19, both P < 0.05). The frequency of bowel movement in group C was significantly higher than that in group A (7.15 ± 1.61 vs 6.54 ± 1.52, t = 2.724, P = 0.023). The intestinal bubble score showed no statistically significant difference among the three groups (F = 0.359, P = 0.699). The incidence of side effects also did not differ significantly among the three groups (16.67%, 13.33% and 6.67%, χ² = 1.450, P = 0.484).

CONCLUSION: Mosapride can effectively improve bowel preparation before colonoscopy in patients with constipation.