The Effect of Obesity on the Quality of Bowel Preparation for Colonoscopy: Results From a Large Observational Study

Incidence and predicting factors of inadequate bowel preparation for colonoscopy: A cross-sectional study

Background and Aim

Adequate bowel preparation is necessary for optimal colonoscopy. Inadequate bowel preparation results in increased costs and imprecise colonoscopy results. This study aims to determine the incidence and risk factors of inadequate bowel preparation.

Methods

In this study, 604 consecutive patients were observed prospectively who underwent colonoscopy examination. The patient's clinical and demographic data were obtained on the day of the procedure. Bowel preparation was evaluated by Boston Bowel Preparation Scale (BBPS) and was divided into two groups; adequate and inadequate. Univariate and multivariate analyses were performed.

Results

Inadequate bowel preparation incidence was 17.9%. In the univariate analysis, education level (P value = 0.009), body mass index (P value = 0.03), admission type (P value = 0.038), previous history of colonoscopy (P value = 0.03), color and consistency of the last feces (P value = 0.03), diabetes (P value = 0.004), and smoking (P value = 0.03) were significantly related with the incidence of inadequate bowel preparation. While ischemic heart disease (IHD) decreased the level of inadequate bowel preparation (P value = 0.047). Multivariate analysis showed that diabetes mellitus (odds ratio [OR] = 2.18), smoking (OR = 2.10), inpatient status of admission type (OR = 3.32), last stool that was non-watery (OR = 1.60), and ischemic heart disease (OR = 0.032) were independent factors associated with inadequate bowel preparation.

Conclusion

Diabetic patients, smokers, inpatients and who defecated a non-watery and colory stool as the last defecation are at risk of inadequate bowel preparation and need more potent regimens. It is important to inform patients about preventable factors that affect bowel preparation to improve their preparation outcomes.

3 L split-dose polyethylene glycol is superior to 2 L polyethylene glycol in colonoscopic bowel preparation in relatively high-BMI (≥ 24 kg/m2) individuals: a multicenter randomized controlled trial

BACKGROUND

Whether body mass index (BMI) is a risk factor for poor bowel preparation is controversial, and the optimal bowel preparation regimen for people with a high BMI is unclear.

METHODS

We prospectively included 710 individuals with high BMIs (≥ 24 kg/m2) who were scheduled to undergo colonoscopy from January to November 2021 at 7 hospitals. Participants were randomly allocated into 3 L split-dose polyethylene glycol (PEG) group (n=353) and 2 L PEG group (n=357). The primary outcome was the rate of adequate bowel preparation, and the secondary outcomes included Boston Bowel Preparation Scale (BBPS) score, polyp detection rate, cecal intubation rate, and adverse reactions during bowel preparation. Furthermore, we did exploratory subgroup analyses for adequate bowel preparation.

RESULTS

After enrollment, 15 individuals didn't undergo colonoscopy, finally 345 participants took 3 L split-dose PEG regimen, and 350 participants took 2 L PEG regimen for colonoscopic bowel preparation. 3 L split-dose PEG regimen was superior to 2 L PEG regimen in the rate of adequate bowel preparation (81.2% vs. 74.9%, P = 0.045), BBPS score (6.71±1.15 vs. 6.37±1.31, P < 0.001), and the rate of polyp detection (62.0% vs. 52.9%, P = 0.015). The cecal intubation rate was similar in both groups (99.7%). Regarding adverse reactions, individuals were more likely to feel nausea in the 3 L PEG group (30.9% vs. 19.3%; P = 0.001); however, the degree was mild. In the subgroup analysis for adequate bowel preparation, 3 L split-dose PEG regimen performed better than 2 L PEG regimen in the overweight (BMI 25-29.9 kg/m2 ) (P = 0.006) and individuals with constipation (P = 0.044), while no significant differences were observed in relatively normal (BMI 24-24.9 kg/m2) (P = 0.593) and obese individuals (BMI ≥ 30 kg/m2) (P = 0.715).

CONCLUSIONS

3 L split-dose PEG regimen is superior to 2 L PEG regimen for colonoscopic Bowel Preparation in relatively high-BMI individuals, especially overweight individuals (BMI 25-29.9 kg/m2 ).

TRIAL REGISTRATION

This trial was registered in the Chinese Clinical Trials Registry (ChiCTR2000039068). The date of first registration, 15/10/2020, http://www.chictr.org.cn.

Comparison of oral sodium phosphate tablets and polyethylene glycol lavage solution for colonoscopy preparation: a systematic review and meta-analysis of randomized clinical trials

Objective

To systematically compare the bowel cleaning ability, patient tolerance and safety of oral sodium phosphate tablets (NaPTab) and oral polyethylene glycol electrolyte lavage solution (PEGL) to inform clinical decision making.

Methods

PubMed, Embase, CBM, WanFang Data, CNKI, and VIP databases were searched for studies that used randomized controlled trials (RCTs) to compare the roles of NaPTab and PEGL in bowel preparation before colonoscopy. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias in the included papers. A meta-analysis was performed using RevMan 5.3 software.

Results

A total of 13 RCTs were eligible for inclusion, including 2,773 patients (1,378 and 1,395 cases in the NaPTab and PEGL groups, respectively). Meta-analysis revealed no significant difference in the cleansing quality of the NaPTab and PEGL groups [RR 1.02, 95% CI (0.96-1.08), P = 0.46]. The incidence of nausea was lower in the NaPTab group than in the PEGL group [RR 0.67, 95% CI (0.58-0.76), p < 0.00001]. Patients rated the taste of NaPTab higher than PEGL [RR 1.33, 95% CI (1.26-1.40), P < 0.00001]. Willingness to repeat the treatment was also higher in the NaPTab group than in the PEGL group [RR 1.52, 95% CI (1.28-1.80), P < 0.00001]. Both serum potassium and serum calcium decreased in both groups after the preparation; however, meta-analysis revealed that both minerals decreased more in the NaPTab group than in the PEGL group [MD = 0.38, 95% CI (0.13-0.62), P = 0.006 for serum potassium and MD = 0.41, 95% CI (0.04-0.77), P = 0.03 for serum calcium]. Meanwhile, serum phosphorus increased in both groups after the preparation; however, levels increased more in the NaPTab group than in the PEGL group [MD 4.51, (95% CI 2.9-6.11), P < 0.00001].

Conclusions

While NaP tablets and PEGL were shown to have a similar cleaning effect before colonoscopy, NaP tablets had improved patient tolerance. However, NaP tablets had a strong effect on serum potassium, calcium, and phosphorus levels. For patients with low potassium, low calcium, and renal insufficiency, NaP tablets should be prescribed with caution. For those at high-risk for acute phosphate nephropathy, NaP tablets should be avoided. Given the low number and quality of included studies, these conclusions will require additional verification by large high-quality studies.

Systematic review registration

10.37766/inplasy2023.5.0013, identifier: NPLASY202350013.

Educating Outpatients for Bowel Preparation Before Colonoscopy Using Conventional Methods vs Virtual Reality Videos Plus Conventional Methods: A Randomized Clinical Trial

IMPORTANCE

Adequate bowel preparation is essential for diagnostic, screening, and surveillance colonoscopy. Virtual reality (VR) has the characteristics of immersion, interaction, and imagination and has been widely used in medicine for training and teaching, indicating that it could be used in the education of outpatients for bowel preparation before colonoscopy.

OBJECTIVE

To investigate whether using VR videos for patient education before colonoscopy could improve bowel preparation.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, single-blinded, randomized clinical trial of 346 patients undergoing colonoscopy with local anesthesia in a tertiary care hospital was conducted between October 1, 2018, and November 1, 2020. Outpatients who had indications for colonoscopy and had not received one before were enrolled. Statistical analysis was performed from November 1 to December 31, 2020. All data were analyzed according to the intention-to-treat approach.

EXPOSURES

Conventional bowel preparation education (oral instructions and written materials that had the same contents) or conventional education plus VR videos.

MAIN OUTCOMES AND MEASURES

The primary outcome was the quality of bowel preparation measured by the Boston Bowel Preparation Scale score (range, 0-9, where 0 indicates extremely unsatisfactory bowel preparation and 9 indicates complete bowel preparation). Secondary outcomes included polyp and adenoma detection rates, compliance with complete bowel cleansing, preprocedure anxiety, overall satisfaction, and willingness to undergo a follow-up colonoscopy.

RESULTS

A total of 346 outpatients were enrolled in the trial, with 173 patients randomly assigned to each group (control group: 87 women [50.3%]; mean [SD] age, 50.5 [12.5] years; VR video group: 84 women [48.6%]; mean [SD] age, 52.6 [11.4] years). Baseline characteristics, including demographic information, medical history, lifestyle, and the characteristics of stool, were comparable between the VR video group and the control group. The mean (SD) Boston Bowel Preparation Scale score was significantly higher in the VR video group than in the control group (7.61 [1.65] vs 7.04 [1.70]; P = .002). The detection rate of polyps (72 of 172 [41.9%] vs 46 of 172 [26.7%]; P = .003) and the detection rate of adenomas (56 of 172 [32.6%] vs 38 of 172 [22.1%]; P = .03) were also higher in the VR video group. Patients who received VR education had better compliance (119 [68.8%] vs 87 [50.3%]; P < .001) and higher mean (SD) overall satisfaction (8.68 [1.70] vs 8.16 [2.15]; P = .01) with bowel preparation.

CONCLUSIONS AND RELEVANCE

Patients who received VR video education before colonoscopy had better bowel preparation, higher polyp and adenoma detection rates, and improved compliance and satisfaction.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03667911.

Risk Factors for Suboptimal Bowel Preparation for Colonoscopy in Pediatric Patients

BACKGROUND/AIMS

Suboptimal bowel cleansing is common in children and can impact diagnostic and therapeutic outcomes. We aimed to identify risk factors for suboptimal bowel preparation for colonoscopy in pediatric patients.

METHODS

This was a retrospective study of all patients ages 0 to 21 years who underwent colonoscopy at a children's hospital from 2015 to 2019 in the United States. Demographics and clinical information were obtained from the electronic health record. The primary outcome was suboptimal bowel preparation measured by the endoscopist on a dichotomized Aronchik Scale. Univariate and multivariate regression modeling were used to determine independent predictors of suboptimal preparation.

RESULTS

Nine hundred and eight patients (mean age 12.17 years [±5.14], boys 465 (51.2%), were included in the analysis. Suboptimal preparation was noted in 242 (26.7%). On univariate analysis, suboptimal preparation was more common in those of younger age (38.6%), Medicaid (32.1%), Spanish as primary language (35.7%), and failure to thrive (FTT) (45.9%). Suboptimal preparations were less common in patients with inflammatory bowel disease (IBD) (11.6%). After adjustment for other covariates, IBD and FTT maintained their statistical associations, IBD (odds ratio [OR] 0.27 95% confidence interval [CI] 0.095-0.75, P =  0.01), FTT (OR 1.98 95% CI 1.28-3.06, P =  <0.01).

CONCLUSIONS

To our knowledge, this is the first investigation of pediatric patients to identify independent risk factors for suboptimal bowel preparation. We confirm Medicaid status and English as a second language as risk factors as well as highlight distinct associations from those reported in the adult literature including FTT and younger age. IBD was associated with optimal cleansing. Future research to understand the mechanisms of inferred risk or potential protection is required.

Low-residue diet for colonoscopy in veterans: Risk factors for inadequate bowel preparation and patient satisfaction and compliance

Bowel preparation with low-residue diet (LRD) has resulted in higher patient satisfaction and similar polyp detection rates compared to conventional clear liquid diet. However, there is limited experience with LRD in veterans, in whom conditions associated with poor bowel preparation are more prevalent than the general population. To examine risk factors associated with inadequate bowel preparation, we conducted a chart review of outpatient colonoscopies at the Manhattan VA Medical Center from February 2017 to April 2018. To examine patient satisfaction and compliance, we administered an anonymous questionnaire to patients undergoing outpatient colonoscopy from March to August 2018. Patients assessed by chart review (n = 660) were 92% male with a mean age of 64 years. An adequate Boston Bowel Preparation Scale score ≥2 in each colonic segment was achieved in 94% of procedures. Higher BMI, diabetes, prior inadequate bowel preparation, bowel preparation duration of two days, and opioid use were associated with inadequate bowel preparation on univariable analysis. On multiple logistic regression, only higher BMI remained a predictor, with every one-unit increase associated with a 6% increased odds of poor bowel preparation. Questionnaire responses showed 84% of patients were willing to repeat LRD bowel preparation, 85% found the process easy or acceptable, and 78% reported full adherence to LRD. These findings demonstrate that bowel preparation quality, patient satisfaction, and compliance were all high among veterans using LRD.

Efficacy, safety, and tolerability of a ready-to-drink bowel preparation in overweight and obese adults: subanalysis by body mass index from a phase III, assessor-blinded study

BACKGROUND

We performed a post hoc secondary analysis for the effect of body mass index (BMI) on the efficacy, tolerability, and safety of ready-to-drink sodium picosulfate, magnesium oxide, and citric acid (SPMC oral solution) bowel preparation.

METHODS

A phase III, randomized, assessor-blinded, multicenter, noninferiority study was conducted comparing split-dose, low-volume SPMC oral solution with a powder formulation for oral solution. A post hoc secondary analysis assessed efficacy, safety, and tolerability of SPMC oral solution stratified by BMI. BMI was classified by Centers for Disease Control and Prevention definitions (underweight and normal weight: BMI < 25 kg/m²; overweight: BMI 25-29.9 kg/m²; class I obesity: BMI 30-34.9 kg/m²; class II obesity: BMI 35-39.9 kg/m²; class III/severe obesity: BMI ⩾40 kg/m²). Prespecified primary efficacy endpoint ('responders') was the proportion of participants with 'excellent' or 'good' ratings on a modified Aronchick Scale (AS). Secondary efficacy outcomes were the quality of cleansing of the right colon as assessed by the Boston Bowel Preparation Scale (BBPS); as well as selected findings from the Mayo Clinic Bowel Prep Tolerability Questionnaire. Safety assessments included adverse events (AEs) and laboratory evaluations.

RESULTS

Between 82.8% and 92.5% of participants in any BMI group were responders by AS, and between 91.3% and 100% were responders by BBPS in the right colon. Efficacy was consistent across BMI groups, with no clear trends. Greater than 83% of participants in any BMI group found the preparation 'easy' or 'acceptable' to ingest, and the majority (>58%) rated SPMC oral solution as 'better' than a prior bowel preparation. In all BMI groups, safety data were similar to the overall cohort. Commonly reported, drug-related, treatment-emergent AEs were, by ascending BMI group, nausea (1.1%, 5.3%, 1.0%, 5.7%, and 0%) and headache (1.1%, 4.1%, 1.0%, 5.7%, and 0%).

CONCLUSIONS

Ready-to-drink SPMC oral solution had consistent, good quality colon cleansing, and favorable tolerability among participants of all BMI groups.

CLINICALTRIALSGOV REGISTRATION

NCT03017235.

Open Access Colonoscopy for Colorectal Cancer Prevention: An Evaluation of Appropriateness and Quality

BACKGROUND

Open access colonoscopy (OAC) has gained widespread acceptance and has the potential to increase colorectal cancer (CRC) screening. However, there is little data evaluating its appropriateness for CRC prevention.

AIMS

The aim of this study is to evaluate the appropriateness of OAC in CRC screening and polyp surveillance by comparing to procedures ordered by gastroenterologists (NOAC). As secondary outcomes, we compared the quality of bowel preparation and adenoma detection rate (ADR) between OAC and NOAC.

METHODS

It is retrospective single-center study. Inclusion criteria included patients > 50 years of age undergoing a colonoscopy for CRC screening and surveillance. Appropriateness was defined as those colonoscopies performed within 12 months of the recommended 2012 consensus guidelines. Secondary outcomes included the quality of bowel preparation and ADR.

RESULTS

5211 colonoscopies met inclusion criteria, and 64.9% were OAC. Screening OAC was appropriately 91.6% and NOAC 92.9% of the time (p = 0.179). Surveillance NOAC were inappropriate in 26.4% of cases, and surveillance OAC was 32.6% (p = 0.008). Multivariate analysis demonstrated that OAC did not influence ADR (OR for NOAC 0.97; 95% CI 0.86-1.1; p = 0.644) or an adequate bowel preparation (OR for NOAC 1.11; 95% CI 0.91-1.36; p = 0.306).

CONCLUSION

OAC performed similarly to NOAC for screening indications, quality of bowel preparation, and ADR. However, more surveillance procedures were inappropriate in the OAC group although both groups had a high number of inappropriate indications. Although OAC can be efficiently performed for screening indications, measures to decrease inappropriate surveillance colonoscopies are needed.