Research Progress of Bowel Preparation for Colonoscopy

Colorectal cancer ranks third in the global cancer data in 2020. Colorectal scope is the most effective method to diagnose colorectal diseases such as benign and malignant colorectal tumors. The poor quality of intestinal preparation causes an increased rate of missed diagnosis of colorectal tumors, reduces the rate of cecal intubation for colorectal examination, increases the discomfort, and reduces the compliance of re-examination. Therefore, we should try our best to improve the quality of intestinal preparation. This study reviewed the latest advances related to the preoperative preparation for colonoscopy. Recent research shows that smartphone apps can provide more detailed education and guidance on bowel preparation;Pre-packaged foods are more suitable as a way to eat before colonoscopy. The use of smaller doses, better taste of cathartic agents, and some auxiliary measures, combined with the patient’s situation to provide personalized intestinal preparation measures to improve the quality of intestinal preparation. Starting from the quality of colonoscopy bowel preparation, continuous improvement of patients’ tolerance to bowel preparation, continuous improvement of bowel preparation plan based on individual factors’ needs, and better communication with examined subjects by using existing scientific information technology, may be the hot spot of colonoscopy bowel preparation research in the next few years.

Research Progress of Bowel Preparation for Colonoscopy

Colorectal cancer ranks third in the global cancer data in 2020.Colorectal scope is the most effective method to diagnose colorectal diseases such as benign and malignant colorectal tumors.The poor quality of intestinal preparation causes an increased rate of missed diagnosis of colorectal tumors,reduces the rate of cecal intubation for colorectal examination,increases the discomfort,and reduces the compliance of re-examination.Therefore,we should try our best to improve the quality of intestinal preparation.This study reviewed the latest advances related to the preoperative preparation for colonoscopy.Recent research shows that smartphone apps can provide more detailed education and guidance on bowel preparation;Pre-packaged foods are more suitable as a way to eat before colonoscopy.The use of smaller doses,better taste of cathartic agents,and some auxiliary measures,combined with the patient’s situation to provide personalized intestinal preparation measures to improve the quality of intestinal preparation.Starting from the quality of colonoscopy bowel preparation,continuous improvement of patients’tolerance to bowel preparation,continuous improvement of bowel preparation plan based on individual factors’needs,and better communication with examined subjects by using existing scientific information technology,may be the hot spot of colonoscopy bowel preparation research in the next few years.

Bowel preparation experiences and needs before follow-up colonoscopy in older adult postoperative colorectal cancer patients: A qualitative study

BACKGROUND The bowel preparation process prior to colonoscopy determines the quality of the bowel preparation,which in turn affects the quality of the colonoscopy.Colono-scopy is an essential procedure for postoperative follow-up monitoring of colorec-tal cancer(CRC)patients.Previous studies have shown that advanced age and a history of colorectal resection are both risk factors for inadequate bowel prepara-tion.However,little attention has been paid to the bowel preparation experiences and needs of predominantly older adult postoperative CRC patients.AIM To explore the experiences and needs of older adult postoperative CRC patients during bowel preparation for follow-up colonoscopy.METHODS Fifteen older adult postoperative CRC patients who underwent follow-up colonoscopy at a tertiary hospital in Shanghai were selected using purposive sampling from August 2023 to November 2023.The phenomenological method in qualitative research was employed to construct an interview outline and conduct semi-structured interviews with the patients.Colaizzi's seven-step analysis was utilized to organize,code,categorize,summarize,and verify the interview data.RESULTS The results of this study were summarized into four themes and eight sub-themes:(1)Inadequate knowledge about bowel preparation;(2)Decreased physiological comfort during bowel preparation(gastrointestinal discomfort and sleep deprivation caused by bowel cleansing agents,and hunger caused by dietary restrictions);(3)Psychological changes during different stages of bowel preparation(pre-preparation:Fear and resistance due to previous experiences;during preparation:Irritation and helplessness caused by taking bowel cleansing agents,and post-preparation:Anxiety and worry while waiting for the colonoscopy);and(4)Needs related to bowel preparation(detailed instructions from healthcare professionals;more ideal bowel cleansing agents;and shortened waiting times for colonoscopy).CONCLUSION Older adult postoperative CRC patients'knowledge of bowel preparation is not adequate,and they may encounter numerous difficulties and challenges during the process.Healthcare professionals should place great emphasis on providing instruction for their bowel preparation.

Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients:Evidence from the literature

Adequate bowel cleansing is critical for a high-quality colonoscopy because it affects diagnostic accuracy and adenoma detection.Nevertheless,almost a quarter of procedures are still carried out with suboptimal preparation,resulting in longer procedure times,higher risk of complications,and higher likelihood of missing lesions.Current guidelines recommend high-volume or low-volume polyethylene glycol(PEG)/non-PEG-based split-dose regimens.In patients who have had insufficient bowel cleansing,the colonoscopy should be repeated the same day or the next day with additional bowel cleansing as a salvage option.A strategy that includes a prolonged low-fiber diet,a split preparation regimen,and a colonoscopy within 5 h of the end of preparation may increase cleansing success rates in the elderly.Furthermore,even though no specific product is specifically recommended in the other cases for difficult-to-prepare patients,clinical evidence suggests that 1-L PEG plus ascorbic acid preparation are associated with higher cleansing success in hospitalized and inflammatory bowel disease patients.Patients with severe renal insufficiency(creatinine clearance<30 mL/min)should be prepared with isotonic high volume PEG solutions.Few data on cirrhotic patients are currently available,and no trials have been conducted in this population.An accurate characterization of procedural and patient variables may lead to a more personalized approach to bowel preparation,especially in patients undergoing resection of left colon lesions,where intestinal preparation has a poor outcome.The purpose of this review was to summarize the evidence on the risk factors influencing the quality of bowel cleansing in difficult-to-prepare patients,as well as strategies to improve colonoscopy preparation in these patients.

Quality of bowel preparation in patients with inflammatory bowel disease undergoing colonoscopy:What factors to consider?

An adequate bowel preparation in patients with inflammatory bowel disease(IBD)is a prerequisite for successful colonoscopy for screening,diagnosis,and surveillance.Several bowel preparation formulations are available,both high-and low-volume based on polyethylene glycol.Generally,low-volume formulations are also based on several compounds such as magnesium citrate preparations with sodium picosulphate,oral sulphate solution,and oral sodium phosphatebased solutions.Targeted studies on the quality of bowel preparation prior to colonoscopy in the IBD population are still required,with current evidence from existing studies being inconclusive.New frontiers are also moving towards the use of alternatives to anterograde ones,using preparations based on retrograde colonic lavage.

Emerging space for non-polyethene-glycol bowel preparations in inflammatory bowel disease-related colonoscopy:Veering toward better adherence and palatability

Patients with inflammatory bowel diseases(IBDs)require repeated endoscopic evaluations over time by colonoscopy to weigh disease activity but also for different and additional indications(e.g.,evaluation of postoperative recurrence,colorectal cancer surveillance).Colonoscopy,however,requires adequate bowel preparation to be of quality.The latter is achieved as long as the patient takes a certain amount of product to have a number of bowel movements suitable to clean the colon and allow optimal visualization of the mucosa during endoscopy.However,significant guidelines recommend preparations for patients with IBD not excelling in palatability.This recommendation originates from the fact that most of the studies conducted on bowel preparations in patients with IBD have been done with isosmolar preparations based on polyethylene glycol(PEG),for which,therefore,more safety data exist.As a result,the low-volume non-PEG preparations(e.g.,magnesium citrate plus picosulphate,oral sulphate solutions)have been set aside for the whole range of warnings to be heeded because of their hyperosmolarity.New studies,however,are emerging,leaning in overall for a paradigm shift in this matter.Indeed,such non-PEG preparations seem to show a particularly encouraging and engaging safety profile when considering their broad potential for tolerability and patient preference.Indeed,such evidence is insufficient to indicate such preparations in all patients with IBD but may pave the way for those with remission or well-controlled disease.This article summarizes the central studies conducted in IBD settings using non-PEG preparations by discussing their results.

Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy

AIM： To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid （PEG ＋ Asc）] and high-volume plus simethicone [polyethylene glycol plus simethicone （PEG ＋ Sim）] bowel preparations. METHODS： A total of one hundred and forty-four outpatients （76 males）, aged from 20 to 84 years （median age 59.5 years）, who attended our Department, were divided into two groups, age and sex matched, and underwent colonoscopy. Two questionnaires, one for patients reporting acceptability and the other for endoscopists evaluating bowel cleansing effectiveness according to validated scales, were completed. Indications, timing of examination and endoscopical findings were recorded. Biopsy forceps were used as a measuring tool in order to determine polyp endoscopic sizeestimation. Difficulty in completing the preparation was rated in a 5-point Likert scale （1 = easy to 5 = unable）. Adverse experiences （fullness, cramps, nausea, vomiting, abdominal pain, headache and insomnia）, number of evacuations and types of activities performed during preparation （walking or resting in bed） were also investigated. RESULTS： Seventy-two patients were selected for each group. The two groups were age and sex matched as well as being comparable in terms of medical history and drug therapies taken. Fourteen patients dropped out from the trial because they did not complete the preparation procedure. Ratings of global bowel cleansing examinations were considered to be adequate in 91% of PEG ＋ Asc and 88% of PEG ＋ Sim patients. Residual Stool Score indicated similar levels of amount and consistency of residual stool; there was a significant difference in the percentage of bowel wall visualization in favour of PEG ＋ Sim patients. In the PEG ＋ Sire group, 12 adenomas≤ 10 mm diameter （5/left colon ＋ 7/right colon） vs 9 （8/left colon ＋ 1/right colon） in the PEG ＋ Asc group were diagnosed. Visualization of small lesions seems to be one of the primary advantages of the PEG ＋ Sim preparation. CONCLUSION： PEG ＋ Asc is a good alternative solution as a bowel preparation but more improvements are necessary in order to achieve the target of a perfect preparation.

Improving quality of colonoscopy by adding simethicone to sodium phosphate bowel preparation

AIM： To evaluate the effectiveness of simethicone in enhancing visibility and efficacy during colonoscopy.METHODS： A prospective, double-blind, randomized, placebo-controlled study was conducted. One hundred and twenty-four patients were allocated to receive 2 doses of sodium phosphate plus 240 mg of tablet simethicone or placebo as bowel preparation. Visibility was blindly assessed for the amount of air bubbles and adequacy of colon preparation. Total colonoscopic time, side effects of the medication, endoscopist and patient satisfaction were also compared.RESULTS： Sodium phosphate plus simethicone, compared to sodium phosphate plus placebo, improved visibility by diminishing air bubbles （100.00% vs 42.37%, P 〈 0.0002） but simethicone failed to demonstrate improvement in adequacy of colon preparation （90.16% vs 81.36%, P = 0.17）. Endoscopist and patient satisfaction were increased significantly in the simethicone group. However, there was no difference in the total duration of colonoscopy and side effects of the medication.CONCLUSION： The addition of simethicone is of benefit for colonoscopic bowel preparation by diminishing air bubbles, which results in enhanced visibility. Endoscopist and patient satisfaction is also increased.

Magnesium citrate with a single dose of sodium phosphate for colonoscopy bowel preparation

AIM:To evaluate the efficacy and acceptability of magnesium citrate and a single dose of oral sodium phosphate(45 mL) solution for morning colonoscopy bowel preparation. METHODS:A total of 159 patients were randomly assigned to receive two split doses of 90 mg of sodium phosphate(GroupⅠ,n=79) or magnesium citrate(250 mL,the day before the procedure) followed by 45 mL of sodium phosphate(the day of procedure,GroupⅡ,n= 80) .The quality of bowel cleansing and the acceptability of each regimen were compared,including the satisfaction,taste,willing to repeat and adverse effects of each regimen. RESULTS:The quality of bowel cleansing of GroupⅡ was as good as that of GroupⅠ(An Aronchick scale score of good or excellent:70.9%vs 81.0%,respectively,P=0.34;the Ottawa system score:4.4±2.6 vs 3.8 ±3.0,respectively,P=0.76) .There was no statisticallysignificant difference between both groups with regard to acceptability,including the satisfaction,taste and willingness to repeat the regimen.A significantly greater number of older patients(over 65 years old) in Group Ⅱgraded the overall satisfaction as satisfactory(48.1% vs 78.1%,respectively;GroupⅠvs GroupⅡ,P=0.01) . There were no significant adverse reactions. CONCLUSION:Magnesium citrate and a single dose of sodium phosphate was as effective and tolerable as the conventional sodium phosphate regimen and is a satisfactory option.

Evidence-based considerations on bowel preparation for colonoscopy

We recently read with interest the article,“Novel frontiers of agents for bowel cleansing for colonoscopy”.This is a practical narrative review,which could be of particular importance to clinicians in order to improve their current practice.Although we appreciate the venture of our colleagues,based on our in-depth analysis,we came across several minor issues in the article;hence,we present our comments in this letter.If the authors consider these comments further in their relevant research,we believe that their contribution would be of considerable importance for future studies.

Analysis of YouTube^(TM) videos related to bowel preparation for colonoscopy

AIM: To examine YouTubeTM videos about bowel preparation procedure to better understand the quality of this information on the Internet. METHODS: YouTubeTM videos related to colonoscopy preparation were identified during the winter of 2014; only those with ≥ 5000 views were selected for analysis(n = 280). Creator of the video, length, date posted, whether the video was based upon personal experience, and theme was recorded. Bivariate analysis was conducted to examine differences between consumers vs healthcare professionals-created videos. RESULTS: Most videos were based on personal experience. Half were created by consumers and 34% were ≥ 4.5 min long. Healthcare professional videos were viewed more often(】 19400, 59.4% vs 40.8%,P = 0.037, for healthcare professional and consumer, respectively) and more often focused on the purgative type and completing the preparation. Consumer videos received more comments(】 10 comments, 62.2% vs 42.7%, P = 0.001) and more often emphasized the palatability of the purgative, disgust, and hunger during the procedure. Content of colonoscopy bowel preparation YouTube? videos is influenced by who creates the video and may affect views on colon cancer screening. CONCLUSION: The impact of perspectives on the quality of health-related information found on the Internet requires further examination.

Ascorbic acid and low-volume polyethylene glycol for bowel preparation prior to colonoscopy:A meta-analysis

AIM: To evaluate the benefits of low-volume polyethylene glycol(PEG) with ascorbic acid compared to fulldose PEG for colonoscopy preparation. METHODS: MEDLINE, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, CINAHL, Pub Med, and recent abstracts from major conferences were searched(January 2012). Only randomized-controlled trials on adult subjects comparing lowvolume PEG(2 L) with ascorbic acid vs full-dose PEG(3 or 4 L) were included. Meta-analysis for the efficacy of low-volume PEG with ascorbic acid and full-dose PEG were analyzed by calculating pooled estimates of number of satisfactory bowel preparations as well as adverse patient events(abdominal pain, nausea, vomiting). Separate analyses were performed for each main outcome by using OR with fixed and random effects models. Heterogeneity was assessed by calculating the I2 measure of inconsistency. Rev Man 5.1 was utilized for statistical analysis.RESULTS: The initial search identified 242 articles and trials. Nine studies(n = 2911) met the inclusion criteria and were analyzed for this meta-analysis with mean age range from 53.0 to 59.6 years. All studies were randomized controlled trials on adult patients comparing large-volume PEG solutions(3 or 4 L) with low-volume PEG solutions and ascorbic acid. No statistically significant difference was noted between lowvolume PEG with ascorbic acid and full-dose PEG for number of satisfactory bowel preparations(OR 1.07, 95%CI: 0.86-1.33, P = 0.56). No statistically significant difference was noted between low-volume PEG with ascorbic acid and full-dose PEG for abdominal pain(OR 1.09, 95%CI: 0.81-1.48, P = 0.56), nausea(OR 0.70, 95%CI: 0.49-1.00, P = 0.05), or vomiting(OR 0.99, 95%CI: 0.78-1.26, P = 0.95). No publication bias was noted.CONCLUSION: Low-volume PEG with the addition of ascorbic acid demonstrates no statistically significant difference to full-dose PEG for satisfactory bowel preparation and side-effects.

Bowel preparation quality scales for colonoscopy

Colorectal cancer(CRC) is the third most common cancer and second leading cause of cancer-related death in the United States. Colonoscopy is widely preferred for CRC screening and is the most commonly used method in the United States. Adequate bowel preparation is essential for successful colonoscopy CRC screening. However, up to one-quarter of colonoscopies are associated with inadequate bowel preparation, which may result in reduced polyp and adenoma detection rates, unsuccessful screens, and an increased likelihood of repeat procedure. In addition, standardized criteria and assessment scales for bowel preparation quality are lacking. While several bowel preparation quality scales are referred to in the literature, these differ greatly in grading methodology and categorization criteria. Published reliability and validity data are available for five bowel preparation quality assessment scales, which vary in several key attributes. However, clinicians and researchers continue to use a variety of bowel preparation quality measures, including nonvalidated scales, leading to potential confusion and difficulty when comparing quality results among clinicians and across clinical trials. Optimal clinical criteria for bowel preparation quality remain controversial. The use of validated bowel preparation quality scales with stringent but simple scoring criteria would help clarify clinical trial data as well as the performance of colonoscopy in clinical practice related to quality measurements.

Bisacodyl plus split 2-L polyethylene glycol-citrate-simethicone improves quality of bowel preparation before screening colonoscopy

AIM:To compare the bowel cleansing efficacy,tolerability and acceptability of split 2-L polyethylene glycol(PEG)-citrate-simethicone(PEG-CS)plus bisacodyl(BIS)vs 4-L PEG for fecal occult blood test-positive screening colonoscopy.METHODS:This was a randomised,observer-blind comparative study.Two hundred and sixty-four subjects underwent screening colonoscopy(mean age 62.5±7.4years,male 61.7%).The primary objective of the study was to compare the bowel cleansing efficacy of the two preparations.Interventions:BIS plus PEG-CS:3 tablets of 5-mg BIS at 16:00,PEG-CS 1-L at 19:00 and 1-L at7:00,4-L PEG:3-L at 17:00,and 1-L at 7:00.Colonoscopy was carried out after 11:00,at least 3 h after the completion of bowel preparation.Bowel cleansing was evaluated using the Harefield Cleansing Scale.RESULTS:Bowel preparation was successful for 92.8%of subjects in the PEG-CS group and for 92.1%of subjects in the 4-L PEG(RR=1.01;95%CI:0.94-1.08).BIS+PEG-CS was better tolerated than 4-L PEG.A greater rate of patients in the BIS+PEG-CS group had no difficulty and/or were willing to repeat the same preparation compared to split-dose 4-L PEG group.Subjects in the BIS+PEG-CS group rated the prep as good or satisfactory in 90.6%as compared to 77%in the 4-L PEG(P=0.003).Subjects receiving BIS+PEGCS stated they fully adhered to instructions drinking all the 2-L solution in 97.1%compared with 87.3%in the4-L PEG(P=0.003).CONCLUSION:BIS plus split 2-L PEG-CS was as effective as but better tolerated and accepted than split4-L PEG for screening colonoscopy.This new procedure may increase the positive attitude and participation to colorectal cancer screening colonoscopy.

Bowel preparation prior to colonoscopy:A continual search for excellence

Bowel preparation prior to colonoscopy is essential to maximize the benefits of colonoscopy.Numerous bowel preparations have been studied,ranging from 4 L polyethylene glycol(PEG) to split-dose regimens to 2 L PEG with an adjunct laxative(senna,bisacodyl,ascorbic acid).Due to the large volume of PEG required for adequate bowel preparation,many studies have focused on reducing this large volume to only 2 L PEG with the addition of an adjunct.Recently,a randomized controlled trial by Tajika et al showed that the addition of mosapride to only 1.5 L PEG was non-inferior to mosapride and 2 L PEG for bowel cleansing but did provide improvements in patient tolerance.This study offers yet another potential bowel preparation for patients undergoing colonoscopy and may trigger further studies with 1.5 L PEG with an adjunct.In this letter,we discuss the current state of bowel preparation prior to colonoscopy and offer information to guide clinicians on choosing the appropriate bowel preparation for their patients.

Comparison of split-dosing vs non-split(morning) dosing regimen for assessment of quality of bowel preparation for colonoscopy

AIM: To compare(using the Ottawa Bowel Preparation Scale) the efficacy of split-dose vs morning administration of polyethylene glycol solution for colon cleansing in patients undergoing colonoscopy, and to assess the optimal preparation-to-colonoscopy interval.METHODS: Single-centre, prospective, randomized, investigator-blind stud in an academic tertiarycare centre. Two hundred patients requiring elective colonoscopy were assigned to receive one of the two preparation regimens(split vs morning) prior to colonoscopy. Main outcome measurements were bowel preparation quality and patient tolerability.RESULTS: Split-dose regimen resulted in better bowel preparation compared to morning regimen [Ottawascore mean 5.52(SD 1.23) vs 6.02(1.34); P = 0.017]. On subgroup analysis, for afternoon procedures, both the preparations were equally effective(P = 0.756). There was no difference in tolerability and compliance between the two regimens.CONCLUSION: Overall, previous evening- same morning split-dosing regimen results in better bowel cleansing for colonoscopy compared to morning preparation. For afternoon procedures, both schedules are equally effective; morning preparation may be more convenient to the patient.

Factors influencing quality of bowel preparation for colonoscopy

Recent technological advances in colonoscopy have led to improvements in both image enhancement and procedural performance.However,the utility of these technological advancements remain dependent on the quality of bowel preparation during colonoscopy.Poor bowel preparation has been shown to be associated with lower quality indicators of colonoscopy performance,such as reduced cecal intubation rates,increased patient discomfort and lower adenoma detection.The most popular bowel preparation regimes currently used are based on either Polyethylene glycol-electrolyte,a non-absorbable solution,or aqueous sodium phosphate,a lowvolume hyperosmotic solution.Statements from various international societies and several reviews have suggested that the efficacy of bowel preparation regimes based on both purgatives are similar,although patients' compliance with these regimes may differ somewhat.Many studies have now shown that factors other than the type of bowel preparation regime used,can influence the quality of bowel preparation among adult patients undergoing colonoscopy.These factors can be broadly categorized as either patient-related or procedure-related.Studies from both Asia and the West have identified patient-related factors such as an increased age,male gender,presence of co-morbidity and socioeconomic status of patients to be associated with poor bowel preparation among adults undergoing routine out-patient colonoscopy.Additionally,procedure-related factors such as adherence to bowel preparation instructions,timing of bowel purgative administration and appointment waiting times for colonoscopy are recognized to influence the quality of colon cleansing.Knowledge of these factors should aid clinicians in modifying bowel preparation regimes accordingly,such that the quality of colonoscopy performance and delivery of service to patients can be optimised.

Electrolyte changes after bowel preparation for colonoscopy:A randomized controlled multicenter trial

AIM:To investigate the electrolyte changes between 2-L polyethylene glycol with ascorbic acid 20 g(PEGAsc) and 4-L PEG solutions.METHODS:From August 2012 to February 2013,a total of 226 patients were enrolled at four tertiary hospitals.All patients were randomly allocated to a PEG-Asc group or a 4-L PEG.Before colonoscopy,patients completed a questionnaire to assess bowel preparation-related symptoms,satisfaction,and willingness.Endoscopists assessed the bowel preparation using the Boston Bowel Preparation Scale(BBPS).In addition,blood tests,including serum electrolytes,serum osmolarity,and urine osmolarity were evaluated both before and after the procedure.RESULTS:A total of 226 patients were analyzed.BBPS scores were similar and the adequate bowel preparation rate(BBPS≥6)was not different between the two groups(PEG-Asc vs 4-L PEG,73.2%vs 76.3%,P=0.760).Bowel preparation-related symptoms also were not different between the two groups.The taste of PEG-Asc was better(41.1%vs 16.7%,P<0.001),and the willingness to undergo repeated bowel preparation was higher in the PEG-Asc group(73.2%vs 59.3%,P=0.027)than in 4-L PEG.There were no significant changes in serum electrolytes in either group.CONCLUSION:In this multicenter trial,bowel preparation with PEG-Asc was better than 4-L PEG in terms of patient satisfaction,with similar degrees of bowel preparation and electrolyte changes.

Bowel preparation for colonoscopy using standard vs reduced doses of sodium phosphate: A single-blind randomized controlled study

AIM: To evaluate the efficacy of a colonoscopy prepa-ration that utilizes a reduced dose of sodium phosphate(NaP) and an adjunct.METHODS: Sixty-two patients requiring screening colonoscopies were studied. Each patient was randomly allocated to receive either 50 NaP tablets(50 g) or 30 NaP tablets(30 g) with 10 mL of 0.75% sodium pico-sulfate for bowel preparation. NaP was administered at a rate of five tablets(5 g) or three tablets(3 g) every 15 min with 200 mL of water, beginning five to six hours before colonoscopy. The sodium picosulfate was administered with 200 mL of water on the night before the procedure. Both groups were compared in term of the efficacies of colonic cleansing, the time required for completion of the bowel preparation, and acceptability of the preparation.RESULTS: Sixty patients(n = 30 for each group) were analyzed. The cleansing efficacy tended to be higher in the 30 g NaP plus sodium picosulfate group as as-sessed by the mean total Ottawa scale score(50 g NaP6.70 ± 1. 42 vs 30 g NaP plus sodium picosulfate 6.17 ± 1.18 P = 0.072). The mean time for bowel prepara-tion tended to be shorter in the 30 g NaP plus sodium picosulfate group(50 g NaP 189.9 ± 64.0 min vs 30 g NaP plus sodium picosulfate 161.8 ± 57.6 min, P = 0.065). There were no significant differences between the two groups in the acceptability of the preparations(50 g NaP 83.3% vs 30 g NaP plus sodium picosulfate 86.7%, P = 0.500). There were no adverse events re-lated to bowel preparation in either of the groups.CONCLUSION: The colonoscopy preparation that uti-lized 30 g NaP with sodium picosulfate was comparable to that utilizing 50 g NaP. This novel bowel preparation might be useful before colonoscopy.

Efficacy of 0.5-L vs 1-L polyethylene glycol containing ascorbic acid as additional colon cleansing methods for inadequate bowel preparation as expected by last stool examination before colonoscopy

BACKGROUND No consensus has been reached in patients suspected of having inadequate bowel preparation regarding optimal salvage methods, which negatively affects the efficacy and quality of colonoscopy. The most ideal and reasonable rescue option involves early suspicion and identification of patients with inadequate preparation before sedation, additional oral ingestion of a suitable preparation formulation, and same-day colonoscopy.AIM To compare 0.5-L and 1-L polyethylene glycol containing ascorbic acid(PEG +Asc) as additional bowel cleansing methods after a 2-L split-dose PEG + Asc regimen in patients with expected inadequate bowel preparation before colonoscopy.METHODS Individuals with expected inadequate bowel preparation based on last stool form, such as turbid liquid, particulate liquid, or liquid with small amounts of feces, were randomized to either a 0.5-L PEG + Asc group or a 1-L PEG + Asc group. The primary endpoint was bowel preparation as assessed using the Aronchick bowel preparation scale(ABPS) and Boston bowel preparation scale(BBPS) scores. The secondary endpoints were cecal intubation time, withdrawal time, polyp detection rate(PDR), adenoma detection rate(ADR), individual compliance with additional PEG + Asc, and patient satisfaction.RESULTS Initially, 98 patients were included, but 8 were later excluded due to withdrawal of consent to participate in the study. Adequate bowel preparation(as assessed by ABPS) was observed in 80.9%(38/47) of subjects in the 0.5-L group and in88.4%(38/43) of subjects in the 1-L group(P = 0.617). Mean total BBPS was 6.7 points in the 0.5-L group and 7.0 points in the 1-L group(P = 0.458). ADRs and PDRs were similar in the two groups, and cecal intubation and withdrawal times were not significantly different. However, mean patient satisfaction score was significantly higher in the 0.5-L group(P = 0.041).CONCLUSION The bowel cleaning efficacy of additional 0.5-L PEG + Asc was not inferior to that of 1-L PEG + Asc. Additional 0.5-L PEG + Asc is worthwhile when inadequate bowel preparation is expected before colonoscopy.