Adenoma detection rate and tolerability of two ultra-low volume bowel preparations in screening: a noninferiority randomized controlled trial.

BACKGROUND AND AIMS: The adenoma detection rate (ADR), recognized as a surrogate marker for colorectal cancer incidence and mortality reduction, is closely linked to the efficacy of bowel cleansing. However, there is a dearth of evidence examining the impact on ADR when employing two distinct very low-dose bowel cleansing products. This study sought to compare ADR in a fecal immunochemical occult blood testing (iFOBT) based organized screening program by utilizing 1L polyethylene glycol plus ascorbate (1L-PEGA) versus magnesium citrate plus picosulphate (SPMC), both administered in a split-dose regimen. METHODS: We conducted a comparative, parallel, randomized, noninferiority, and low-intervention clinical trial, the study targeted individuals from a population colorectal cancer screening program aged 50-69 with a positive iFOBT result scheduled for a work-up colonoscopy in the morning. Participants were randomized to either 1L-PEGA or SPMC for bowel cleansing. Main outcome was ADR. Secondary outcomes were bowel preparation quality, individuals' safety, tolerability and satisfaction. RESULTS: A total of 1,002 subjects were included, 501 in each group. There were no differences between groups with respect to pooled ADR (SPMC, 56.5% [52.1-60.8]; 1L-PEGA, 53.7% [49.3-58.0]; RR 0.95 [0.85-1.06]); therefore, SPMC demonstrated noninferiority in ADR compared to 1L-PEGA (difference, 2.8%; 2-sided 95% lower confidence limit (LCL), -3.4). In addition, there were no significant differences in mean lesions regardless of size and location between arms. Bowel preparation favored 1L-PEGA (96.2% vs. 89.2%; p<0.001) whereas SPMC exhibited significantly higher safety and tolerability, as evidenced by fewer non-serious treatment-emergent adverse events CONCLUSIONS: SPMC emerged as a noninferior laxative compared to 1L-PEGA concerning ADR. Despite the superior bowel preparation quality associated with 1L-PEGA, the safety, tolerability and overall satisfaction of participants were higher with SPMC. This trial was registered at ClinicalTrials.gov (EudraCT: 2019-003186-18) on March 18, 2019.

A randomized prospective study comparing the effect of low-volume bowel preparations for colonoscopy preparation in China.

AIM: To evaluate the effect of sodium picosulfate/magnesium citrate (SPMC) and 3 L split-dose polyethylene glycol (PEG) with or without dimethicone on bowel preparation before colonoscopy. METHODS: In this multicenter, prospective, randomized, controlled study conducted from April 2021 to December 2021, consecutive adult patients scheduled for colonoscopy were prospectively randomized into four groups: SPMC, SPMC plus dimethicone, 3 L PEG, and 3 L PEG plus dimethicone. Primary endpoint was colon cleansing based on Boston Bowel Preparation Scale (BBPS). Secondary endpoints were bubble score, time to cecal intubation, adenoma detection rate (ADR), patient safety and compliance, and adverse events. RESULTS: We enrolled 223 and 291 patients in SPMC and 3 L PEG group, respectively. The proportion with acceptable bowel cleansing, total BBPS score and cecal intubation time were similar in all four subgroups (p > 0.05). Patient-reported acceptability and tolerability was significantly greater in SPMC than 3 L PEG group (p < 0.001); adverse events were significantly lower in SPMC than latter group (p < 0.001). ADR in both groups was greater than 30%. CONCLUSION: SPMC had significantly higher acceptability and tolerability than 3 L PEG, however, was similar in terms of bowel-cleansing effect and cecal intubation time and hence can be used before colonoscopy preparation.

Impact of inadequate bowel cleansing in sigmoidoscopy screening.

BACKGROUND AND STUDY AIMS: Long-time follow-up of sigmoidoscopy screening trials has shown reduced incidence and mortality of colorectal cancer (CRC), but inadequate bowel cleansing may hamper efficacy. The aim of this study was to assess the impact of bowel cleansing quality in sigmoidoscopy screening. PATIENTS AND METHODS: Individuals 50 to 74 years old who had a screening sigmoidoscopy in a population-based Norwegian, randomized trial between 2012 and 2019, were included in this cross-sectional study. The bowel cleansing quality was categorised as excellent, good, partly poor, or poor. The effect of bowel cleansing quality on adenoma detection rate (ADR) and referral to colonoscopy was evaluated by fitting multivariable logistic regression models. RESULTS: 35,710 individuals were included. The bowel cleansing at sigmoidoscopy was excellent in 20,934 (58.6%) individuals, good in 6580 (18.4%), partly poor in 7097 (19.9%) and poor in 1099 (3.1%). The corresponding ADRs were 17.0%, 16.6%, 14.5%, and 13.0%. Compared to participants with excellent bowel cleansing, those with poor bowel cleansing had an odds ratio for adenoma detection of 0.66 (95% confidence interval 0.55-0.79). We found substantial differences in the assessment of bowel cleansing quality among endoscopists. CONCLUSIONS: Inadequate bowel cleansing reduces the efficacy of sigmoidoscopy screening, by lowering ADR. A validated rating scale and improved bowel preparation are needed to make sigmoidoscopy an appropriate screening method.Trial registration Clinicaltrials.gov (NCT01538550).

Effect of bowel preparation completion time on bowel cleansing efficacy: Prospective randomized controlled trial of different bowel preparation completion times precolonoscopy.

OBJECTIVES: The elapse time between the completion of bowel cleansing and colonoscopy is one of the important factors for proper bowel cleansing. Although several studies have reported that a short time interval resulted in a favorable bowel cleansing, no randomized controlled trial (RCT) has been conducted to determine the effect of the elapse time. Consequently, we performed an RCT to investigate the efficacy of bowel preparation of participants who underwent colonoscopy according to the different time intervals between the completion of bowel preparation and colonoscopy. METHODS: In this single-center RCT, study participants were randomized to complete bowel preparation either 2-4 h or 4-8 h before colonoscopy. The primary end-point was successful bowel preparation, rated using the Boston Bowel Preparation Scale (BBPS). RESULTS: A total of 504 individuals were included (2-4 h, 255; 4-8 h, 249). The rate of successful bowel preparation in the 2-4 h group showed noninferiority compared with that of the 4-8 h group (97.6% vs. 95.2%; rate difference, 2.5% [-0.8% to 5.7%]; Pfor noninferiority < 0.001, Pfor superiority = 0.136). The rate for perfect cleansing (a BBPS score of 9) was higher in the 2-4 h group (56.5% vs. 39.8%, P < 0.001). CONCLUSION: When bowel cleansing was finished 2-4 h before the start of colonoscopy, the overall bowel cleansing was noninferior, and perfect cleansing was superior, compared to that when cleansing was finished 4-8 h before colonoscopy.

Design and validation of an artificial intelligence system to detect the quality of colon cleansing before colonoscopy.

BACKGROUND AND AIMS: Patients' perception of their bowel cleansing quality may guide rescue cleansing strategies before colonoscopy. The main aim of this study was to train and validate a convolutional neural network (CNN) for classifying rectal effluent during bowel preparation intake as "adequate" or "inadequate" cleansing before colonoscopy. PATIENTS AND METHODS: Patients referred for outpatient colonoscopy were asked to provide images of their rectal effluent during the bowel preparation process. The images were categorized as adequate or inadequate cleansing based on a predefined 4-picture quality scale. A total of 1203 images were collected from 660 patients. The initial dataset (799 images), was split into a training set (80%) and a validation set (20%). The second dataset (404 images) was used to develop a second test of the CNN accuracy. Afterward, CNN prediction was prospectively compared with the Boston Bowel Preparation Scale (BBPS) in 200 additional patients who provided a picture of their last rectal effluent. RESULTS: On the initial dataset, a global accuracy of 97.49%, a sensitivity of 98.17% and a specificity of 96.66% were obtained using the CNN model. On the second dataset, an accuracy of 95%, a sensitivity of 99.60% and a specificity of 87.41% were obtained. The results from the CNN model were significantly associated with those from the BBPS (P<0.001), and 77.78% of the patients with poor bowel preparation were correctly classified. CONCLUSION: The designed CNN is capable of classifying "adequate cleansing" and "inadequate cleansing" images with high accuracy.

Agreement between the perception of colon cleansing reported by patients and colon cleansing assessed by a validated colon cleansing scale.

AIMS: Patients' perception of their cleansing quality can guide strategies to improve cleansing during colonoscopy. There are no studies assessing the agreement between the quality of cleansing perceived by patients and cleansing quality assessed during colonoscopy using validated bowel preparation scales. The main aim of this study was to compare the cleansing quality reported by patients with the quality during colonoscopy using the Boston Bowel Preparation Scale (BBPS). PATIENTS AND METHODS: Consecutive patients referred to an outpatient colonoscopy were included. Four drawings representing different degrees of cleansing were designed. Patients chose the drawing that most resembled the last stool. The predictive ability of the patient's perception and agreement between the patient's perception and the BBPS were calculated. A BBPS score of <2 points in any segment was considered inadequate. RESULTS: Six hundred and thirty-three patients were included (age: 62.8±13.7 years, male: 53.4%). Overall, 107 patients (16.9%) had inadequate cleansing during colonoscopy, and in 12.2% of cases, the patient's perception was poor. The patient's perception compared to the quality of cleanliness during colonoscopy presented a positive and negative predictive value of 54.6% and 88.3%, respectively. The agreement between patient perception and the BBPS was significant (P<0.001), although fair (k=0.37). The results were similar in a validation cohort of 378 patients (k=0.41). CONCLUSIONS: The cleanliness perceived by the patient and the quality of cleanliness using a validated scale were correlated, although fair. However, this measure satisfactorily identified patients with adequate preparation. Cleansing rescue strategies may target patients who self-report improper cleaning. Registration number of the trial: NCT03830489.

Preoperative Mechanical Bowel Preparation for Gynecologic Surgeries: A Systematic Review with Meta-analysis.

OBJECTIVE: To assess the efficacy and safety of mechanical bowel preparation (MBP) before benign laparoscopic or vaginal gynecologic surgeries. DATA SOURCES: Database searches of MEDLINE (PubMed), Embase (OVID), Cochrane Central Register of Controlled Trials, and Web of Sciences and citations and reference lists published up to December 2021. METHODS OF STUDY SELECTION: Randomized clinical trials in any language comparing MBP with no preparation were included. Two reviewers independently screened 925 records and extracted data from 12 selected articles and assessed the risk of bias with the Cochrane risk-of-bias tool for randomized trials tool. A random-effects model was used for the analysis. Surgeon findings (surgical field view, quality of bowel handling and bowel preparation), operative outcomes (blood loss, operative time, length of stay, surgical site infection), and patient's preoperative symptoms and satisfaction were collected. TABULATION, INTEGRATION, AND RESULTS: Thirteen studies (1715 patients) assessing oral and rectal preparations before laparoscopic and vaginal gynecologic surgeries were included. No significant differences were observed with or without MBP on surgical field view (primary outcome, risk ratio [RR] 1.01, 95% confidence interval [CI] 0.97-1.05, p = .66, I2 = 0%), bowel handling (RR 1.01, 95% CI 0.95-1.08, p = .78, I2 = 67%), or bowel preparation. In addition, there were no statistically significant differences in perioperative findings. MBP was associated with increased pain (mean difference [MD] 11.62[2.80-20.44], I2 = 76, p = .01), weakness (MD 10.73[0.60-20.87], I2 = 94, p = .04), hunger (MD 17.52 [8.04-27.00], I2 = 83, p = .0003), insomnia (MD 10.13[0.57-19.68], I2 = 82, p = .04), and lower satisfaction (RR 0.68, 95% CI 0.53-0.87, I2 = 76%, p = .002) compared with controls. CONCLUSIONS: MBP has not been associated with improved surgical field view, bowel handling, or operative outcome. However, in view of the adverse effects induced, its routine use before benign gynecologic surgeries should be abandoned.

Adherence to the bowel cleansing regimen for pan-enteric capsule endoscopy in patients with suspected Crohn's disease and factors affecting the image quality.

OBJECTIVE: Pan-enteric capsule endoscopy (CE) is an attractive diagnostic approach in patients examined for Crohn's disease (CD). The aim of this study was to examine the adherence to the recommended bowel cleansing regimen and determine clinical factors affecting the image quality. METHODS: In a prospective blinded trial, patients with suspected CD were examined with the PillCam Crohn's capsule after bowel preparation with 2 + 2 L of polyethylene glycol (PEG) and sodium phosphate booster. The image quality was graded on a four-point scale. A good or excellent image quality defined a diagnostic procedure. RESULTS: Fifty-nine patients participated. The mean volume of PEG was 2.5 L (CI 2.3-2.8). Ten patients (17%) were able to drink all 4 L of PEG, and 44 patients (75%) ingested ≥2 L. The image quality was poor, fair, good or excellent in 0%, 29.3%, 29.3% and 41.4%, respectively. The mean volume of PEG was 1.9 L (CI 1.4-2.4), 2.2 L (CI 1.8-2.7) and 3.2 L (CI 2.8-3.5) in patients with a fair, good or excellent image quality (p < .001). In a regression analysis, only the volume of PEG was associated with the obtained image quality (rs=0.52; p < .001). The diagnostic yield was equal in patients with a diagnostic or non-diagnostic procedure (43.9% and 47.1%, respectively). CONCLUSIONS: In patients examined with pan-enteric CE for suspected CD, the volume of PEG is the major factor affecting the image quality. Although few patients are able to ingest the recommended volume, the diagnostic yield is not affected.

Effects of bowel preparation on intestinal bacterial associated urine and faecal metabolites and the associated faecal microbiome.

BACKGROUND: Urinary and faecal metabolic profiling have been extensively studied in gastrointestinal diseases as potential diagnostic markers, and to enhance our understanding of the intestinal microbiome in the pathogenesis these conditions. The impact of bowel cleansing on the microbiome has been investigated in several studies, but limited to just one study on the faecal metabolome. AIM: To compare the effects of bowel cleansing on the composition of the faecal microbiome, and the urine and faecal metabolome. METHODS: Urine and faecal samples were obtained from eleven patients undergoing colonoscopy at baseline, and then at day 3 and week 6 after colonoscopy. 16S rRNA gene sequencing was used to analyse changes in the microbiome, and metabonomic analysis was performed using proton nuclear magnetic resonance (1H NMR) spectroscopy. RESULTS: Microbiomic analysis demonstrated a reduction in alpha diversity (Shannon index) between samples taken at baseline and three days following bowel cleansing (p = 0.002), and there was no significant difference between samples at baseline and six weeks post colonoscopy. Targeted and non-targeted analysis of urinary and faecal bacterial associated metabolites showed no significant impact following bowel cleansing. CONCLUSIONS: Bowel cleansing causes a temporary disturbance in bacterial alpha diversity measured in faeces, but no significant changes in the faecal and urine metabolic profiles, suggesting that overall the faecal microbiome and its associated metabolome is resistant to the effects of an induced osmotic diarrhoea.

1L NER1006 can improve rates of adequate and high-quality bowel cleansing in the right colon: a post hoc analysis of two randomised clinical trials.

BACKGROUND: The right colon is difficult to cleanse compared with other colon segments. This post hoc analysis of two randomised clinical trials (MORA and NOCT) examined whether 1L polyethylene glycol (PEG) NER1006 and two mid-volume alternatives could improve adequate and high-quality cleansing in the right colon among patients with complete cleansing assessments. METHODS: Patients received NER1006 (N2D), 2L PEG plus ascorbate (2LPEG) or oral sulphate solution (OSS) as a 2-day evening/morning split-dosing regimen or NER1006 as a same-day morning-only dosing regimen (N1D). Patients had full segmental scoring assigned by treatment-blinded central readers using the Harefield Cleansing Scale. The right colon adequate (score ≥ 2) and high-quality (score ≥ 3) cleansing success of NER1006 (N2D and N1D) versus 2LPEG and OSS was analysed individually and as pooled groups (N2D vs. 2LPEG/OSS). We assessed the comparative right colon cleansing rates of the N2D versus 2LPEG/OSS in overweight males. We also performed a multivariable regression analysis to examine factors affecting cleansing in the right colon. RESULTS: A total of 1307 patients were included. Pooled N2D showed significantly improved rates of adequate-level cleansing in the right colon compared with 2LPEG (97.5% [504/517] vs. 94.6% [246/260]; p = 0.020) and OSS (97.5% [504/517] vs. 93.8% [244/260]; p = 0.006). In MORA, the rate of adequate right colon cleansing did not significantly differ between N1D and 2LPEG (95.2% [257/270] vs. 94.6% [246/260]; p = 0.383). The rate of right colon high-quality cleansing was significantly improved with N2D or N1D vs. 2LPEG (p < 0.001 for both), and was numerically higher with N2D versus OSS (p = 0.11). In overweight males, NER1006 delivered numerically higher adequate (p = 0.398) and superior high-quality (p = 0.024) cleansing rates versus 2LPEG/OSS. Multivariable regression analysis showed NER1006 was associated with adequate and high-quality cleansing (p = 0.031 and p < 0.001), while time between preparation and colonoscopy was negatively associated (p = 0.034 and p = 0.006). CONCLUSIONS: NER1006 delivered improved rates of adequate and high-quality right colon cleansing compared with 2LPEG and OSS. The increased rate of high-quality cleansing with NER1006 versus its comparators was also seen in overweight males.

Predicting Inadequate Bowel Preparation When Using Sodium Picosulfate plus Magnesium Citrate for Colonoscopy: Development and Validation of a Prediction Score.

INTRODUCTION: Sodium picosulfate plus magnesium citrate is a bowel preparation agent with high patient acceptability. However, it is unclear which patients are more likely to have inadequate bowel preparation when using this agent. This study aimed to identify the risk factors for inadequate bowel preparation when using sodium picosulfate plus magnesium citrate for colonoscopy and to develop a scoring model to predict which patients will have inadequate bowel preparation. METHODS: A total of 350 Japanese patients were enrolled from June 2021 to April 2022. Data on patient background, details of colonoscopy, and satisfaction assessment questionnaire results were prospectively collected. The scoring model for inadequate bowel preparation was developed based on multiple logistic regression analyses, and its performance was internally validated using bootstrapping. RESULTS: Adequate bowel preparation was obtained in 295 patients (84.3%); 335 (95.7%) were able to ingest the drug without difficulty. The scoring model consisted of five independent risk factors and points of risk scores were assigned to each one as follows: American Society of Anesthesiologists physical status III (1 point), diabetes comorbidities (5 points), use of laxatives (4 points), no defecation once in a day (2 points), and drug use for mental disorder (6 points). The C-statistics of the scoring system for inadequate bowel preparation was 0.75. DISCUSSION: We identified five risk factors for inadequate bowel preparation when using sodium picosulfate plus magnesium citrate regimen and developed a scoring model for inadequate bowel preparation with satisfactory discrimination and calibration.

Comparison of 2 L Polyethylene Glycol Plus Ascorbic Acid and 4 L Polyethylene Glycol in Elderly Patients Aged 60-79: A Prospective Randomized Study.

BACKGROUND: The bowel-cleansing efficacy and safety of 2 L polyethylene glycol (PEG) with ascorbic acid (2L PEG + Asc) has rarely been studied in the elderly population. In this randomized trial, we compared the bowel cleanliness, safety, and tolerability of 2L PEG + Asc with those of 4 L PEG in an elderly population aged 60-79. METHODS: Study participants were randomized either to 2L PEG + Asc or 4L PEG. The primary endpoint was the success rate of bowel preparation, using the Boston Bowel Preparation Scale. Before colonoscopy, all participants were questioned about adverse events and tolerability regarding purgative ingestion. RESULTS: A total of 347 individuals were enrolled (2L PEG + Asc, 174; 4L PEG, 173). Mean age in the 2L PEG + Asc and the 4L PEG was 69.3 ± 5.6 and 69.3 ± 5.0, respectively (P = 0.917). The rate for successful bowel cleansing was comparable between the 2L PEG + Asc (92%) and the 4L PEG (96%, P = 0.118). Total ingested liquid including purgative and water was lower in the 2L PEG + Asc group (2.9 L) than in the 4L PEG group (4.2 L, P < 0.001). The tolerability of purgative was superior in the 2L PEG + Asc (overall satisfaction, P < 0.001; willingness to reuse, P < 0.001). There were no serious adverse events during the trial. CONCLUSIONS: The bowel-cleansing efficacy of 2L PEG + Asc was comparable to that of 4L PEG. Tolerability was superior in the 2L PEG + Asc group. For older people, 2L PEG + Asc is an efficacious and safe bowel cleanser. (Clinical trial registration number: KCT0004123).

Efficacy of elobixibat as bowel preparation agent for colonoscopy: Prospective, randomized, multi-center study.

BACKGROUND AND AIM: Elobixibat is a novel ileal bile acid transporter inhibitor. This study aimed to compare the efficacy, tolerability, and safety of the combination of elobixibat and 1 L of polyethylene glycol formulation containing ascorbic acid (PEG-Asc) solution versus the combination of sodium picosulfate and 1-L PEG-Asc solution as bowel preparation for colonoscopy. METHODS: This multi-center, randomized, observer-blinded, non-inferiority study recruited 210 outpatients who were assigned to either the elobixibat plus 1-L PEG-Asc group (group A) or the sodium picosulfate plus 1-L PEG-Asc group (group B). The quality of the bowel cleansing level was assessed by the Boston Bowel Preparation Scale (BBPS) and compared the bowel cleansing level between the groups. Data regarding bowel preparation time, patients' tolerability, and adverse events were also analyzed. RESULTS: Data for 196 patients (99 in group A and 97 in group B) were analyzed finally. BBPS was comparable between group A and B (8.3 ± 0.9 vs. 8.3 ± 0.7; P = 0.88). Consequently, the adequate bowel preparation rate in groups A and B was 95.0% and 99.0%, respectively (-4.0%, 95% CI -9.3 to 1.5). Bowel preparation time in group A was similar to that in group B (348.2 ± 79.8 min vs. 330.8 ± 82.5 min; P = 0.13), whereas, sleep disturbance was significantly less frequent in group A than in group B (10.2% vs. 22.7%; P = 0.02). CONCLUSIONS: The combination of elobixibat and 1-L PEG-Asc can be considered an alternative bowel preparation for colonoscopy considering the equivalent bowel cleansing effect and less frequent sleep disturbance. The Japan Registry of Clinical Trials (jRCTs41180026).

Predictive factors for inadequate bowel cleansing in colon capsule endoscopy.

BACKGROUND AND AIMS: Achieving adequate bowel cleansing is of utmost importance for the efficiency of colon capsule endoscopy (CCE). However, information about predictive factors is lacking. The aim of this study was to assess the predictive factors of poor bowel cleansing in the CCE setting. METHODS: In this observational study, 126 patients who underwent CCE at two tertiary care hospitals were included between June 2017 and January 2020. Participants prepared for bowel cleansing with a 1-day clear liquid diet, a 4-L split-dose polyethylene glycol regimen and boosters with sodium phosphate, sodium amidotrizoate and meglumine amidotrizoate. Domperidone tablets and bisacodyl suppositories were administered when needed. Overall and per-segment bowel cleansing was evaluated using a CCE cleansing score. Simple and multiple logistic regression analysis were carried out to assess poor bowel cleansing and excretion rate predictors. RESULTS: Overall bowel cleansing was optimal in 53 patients (50.5%). Optimal per-segment bowel cleansing was achieved as follows: cecum (86 patients; 74.8%), transverse colon (91 patients; 81.3%), distal colon (81 patients; 75%) and rectum (64 patients; 66.7%). In the univariate analysis, elderly (OR, 1.03; 95% CI (1.01-1.076)) and constipation (OR, 3.82; 95% CI (1.50-9.71)) were associated with poor bowel cleansing. In the logistic regression analysis, constipation (OR, 3.77; 95% CI (1.43-10.0)) was associated with poor bowel cleansing. No variables were significantly associated with the CCE device excretion rate. CONCLUSION: Our results suggest that constipation is the most powerful predictor of poor bowel cleansing in the CCE setting. Tailored cleansing protocols should be recommended for these patients.

Increasing the low residue diet to 3 days does not improve the bowel cleansing in hard to prepare patients: Post hoc analysis of a randomized controlled trial.

BACKGROUND: Recent evidence suggests that the number of low residue diet (LRD) days does not influence the bowel cleansing quality in non-selected patients. However, there are not data in the subgroup of patients with risk factors of inadequate bowel cleansing. OBJECTIVE: The aim of this study was to assess whether a 3-day LRD improved the bowel cleansing quality in patients with risk factors of poor bowel cleansing. PATIENTS AND METHODS: Post hoc analysis of a randomized controlled trial carried out between December 2017 and March 2018 in a tertiary care hospital. Patients with high risk of poor bowel cleansing were selected following a validated score. The patients were randomized to the 1-day LRD or 3-day LRD groups. All patients received a 2-L split-dose of polyethylene glycol plus ascorbic acid. Intention-to-treat (ITT) and per-protocol (PP) analyses were conducted for the main outcome. RESULTS: 135 patients (1-day LRD group=67, 3-day LRD=68) were included. The rate of adequate cleansing quality was not significantly different between the groups in the ITT analysis: 76.1%, 95% CI: [64.6-84.8] vs. 79.4%, 95% CI: [68.2-87.4]; odds ratio (OR) 1.2, 95% CI [0.54-2.73]) or in the PP analysis: 77.3%, 95% CI: [65.7-85.8] vs. 80.3%, 95% CI: [69.0-88.3]; OR 1.2, 95% CI [0.52-2.77]). Compliance with the diet or cleansing solution, satisfaction or difficulties with the LRD and the polyp/adenoma detection rates were not significantly different. CONCLUSION: Our results suggest that 1-day LRD is not inferior to 3-day LRD in patients with risk factors of inadequate bowel cleansing.

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.

Comparison of bowel-cleansing efficacy of split-dose and same-day dose bowel preparation for afternoon colonoscopy in patients with gastrectomy: a prospective randomized study.

BACKGROUND: A split dose (SPD) of purgative is the recommended bowel-preparation method for colonoscopy, although for colonoscopy scheduled for the afternoon, a same-day dose (SDD) of purgative is recommended. However, it has not been determined whether SPD or SDD is better in patients with gastrectomy who are at high risk of suboptimal bowel cleansing. We compared the bowel-cleansing efficacy of SPD and SDD regimens in patients with gastrectomy who underwent colonoscopy in the afternoon. METHODS: This was a prospective, randomized, assessor-blinded study. For the SDD group, polyethylene glycol (PEG) was ingested on the day of colonoscopy starting at 7 AM. In the SPD group, 2 L PEG was ingested at 9 PM the day before colonoscopy, and the remaining 2 L from 10 AM on the day of colonoscopy. Colonoscopy was performed from 1:30 PM. Before colonoscopy, the participants completed questionnaires asking about bowel-movement kinetics, adverse events, tolerability, overall satisfaction, and willingness to reuse the protocol. The bowel-cleansing efficacy was assessed using the Boston Bowel Preparation Scale. RESULTS: A total of 193 subjects were included (SDD, 95; SPD, 98). The rate of successful bowel cleansing was comparable between the two groups (SDD, 92.6% vs. SPD, 95.9%; P = 0.37). The incidence of adverse events (nausea, vomiting, bloating, abdominal pain, and dizziness/headache) was also comparable between the two groups. However, sleep disturbance was higher in the SPD group (SDD, 10.5% vs. SPD, 25.5%; P = 0.01). Tolerability did not differ between the SDD and SPD groups (satisfaction, P = 0.11; willingness to reuse, P = 0.29). CONCLUSIONS: The bowel-cleansing efficacy, safety profile, and patient tolerability of SDD and SPD were comparable. Both SDD and SPD regimens are feasible bowel-preparation methods for patients with gastrectomy who undergo colonoscopy in the afternoon. TRIAL REGISTRATION: Clinical trial registration number: KCT0002699.

Novel 1 L polyethylene glycol-based bowel preparation (NER1006): proof of concept assessment versus standard 2 L polyethylene glycol with ascorbate - a randomized, parallel group, phase 2, colonoscopist-blinded trial.

BACKGROUND: Colonoscopy requires colon cleansing. For this, many polyethylene glycol (PEG)-based preparations still require a high preparation-volume intake. Using an increased osmotic load with ascorbate (Asc), five new low-volume PEG-based bowel preparations (LVPEG) were tested for clinical proof of concept. METHODS: This two-part, open-label study examined preparation-volumes of 1-1.25 L and total required fluid volumes of 2-3 L. Part 1, in healthy volunteers, used mean cumulative 24-h stool weight (target > 2750 g) to identify a lead candidate. Part 2 was endoscopist-blinded: patients undergoing screening colonoscopy were randomized before treatment with the selected lead, one of two variants of it, or the control 2 L PEG + Asc. Two primary endpoints were used for proof of concept demonstration: mean 24-h stool weight and bowel cleansing success (Harefield Cleansing Scale). RESULTS: A total of 120 subjects (30 per group) were enrolled/randomized 1:1:1:1 (max 40:60 gender ratio) per completed Part. In Part 1, LVPEG-3 achieved the largest mean stool weight (3399 g: P < 0.0001 vs target) and was selected for Part 2. In Part 2, stool weights exceeded the target, notably for LVPEG-4 (3215 g: P < 0.001), which achieved 100% cleansing success after a total required fluid intake of 2 L. The control achieved 90% cleansing success. Adverse events were few, gastrointestinal in nature and similar between groups. CONCLUSIONS: LVPEG-4 achieved a clinically useful combination of cleansing, safety/tolerability and low consumption volume: 1 L preparation + 1 L required additional fluid. Named NER1006, LVPEG-4 demonstrated clinical proof of concept and warrants further investigation. TRIAL REGISTRATION: October 2012. Identifier: NCT01714466 . EudraCT: 2012-003052-37 The trial was prospectively registered.

Strategies to optimise the quality of bowel cleansing. / Estrategias para optimizar la calidad de la limpieza colónica.

Colonoscopy is the gold standard procedure for detecting neoplastic lesions of the colon and its efficiency is closely linked to the quality of the procedure. Adequate bowel preparation is a crucial factor in achieving the recommended quality indicators, but poor preparation has been reported in up to 30% of outpatients referred for colonoscopy. Consequently, over recent years, a number of studies have developed strategies to optimise bowel cleansing by improving adherence and tolerance to and the efficacy of the bowel preparation. Moreover, the identification of risk factors for inadequate bowel cleansing has led to tailored bowel preparation strategies being designed, with promising results. We aimed to review studies that assessed risk factors for inadequate bowel preparation and strategies to optimise bowel cleansing in patients at high risk of having poor preparation.

Can coffee or chewing gum decrease transit times in Colon capsule endoscopy? A randomized controlled trial.

BACKGROUND: A high rate of complete colon capsule endoscopy (CCE) investigations is required for a more widespread use of CCE. The objective of this study was to assess if coffee or chewing gum can increase excretion of the colon capsule within battery life time (excretion rate). METHODS: One hundred eighty six screening participants with a positive immunochemical fecal occult blood test were included in this single-centre randomized controlled trial with blinding of the investigators to the randomization. Participants received instant coffee, chewing gum or nothing in addition to the standard bowel preparation. RESULTS: The intention was to include 57 participants in the coffee group, 61 in the chewing gum group and 60 in the control group, on 8 participants data were missing. A total of 165 participants were included in a per protocol analysis. Exclusion was due to not receiving the allocated intervention (8 coffee, 4 chewing gum) and technical failure of the capsule (1 coffee). The excretion rate was 58% in the coffee group (n = 48), 63% in the chewing gum group (n = 57) and 55% in the control group (n = 60, p > 0.2). Transit times were similar in all groups. The excretion rate was low in participants who had transit times over 10 h (14%). A strong correlation was found between adequate cleansing and excretion of the capsule. There were no serious adverse events related to the interventions or CCE investigations. CONCLUSIONS: Chewing gum and coffee did not improve excretion rate in this study. An effect of chewing gum could not be proven, possibly due to sample size. Since chewing gum might improve excretion rates, is cheap and has no known side effects, it needs to be considered in future bowel preparation trials for CCE. TRIAL REGISTRATION: NCT02303756 , registered on December 1st 2014.