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.

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.

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.

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.

Anaphylactic shock induced by polyethylene glycol after bowel preparation for the colorectal cancer surgery:A case report

BACKGROUND Polyethylene glycol(PEG)is widely used as an additive because of its hydrophilic and chemically inert properties.However,there are been increasing reports of PEG allergies,including anaphylaxis,although they are still rare.This case report aims to raise awareness,that the commonly used bowel cleansing agent containing PEG can cause serious allergic reactions.CASE SUMMARY Prior to surgery for sigmoid colon cancer,a 63-year-old man was prescribed a bowel cleansing agent containing PEG.Within 30 min of ingestion,he developed symptoms of anaphylactic shock and did not respond to initial intramuscular epinephrine injection.Under diagnosis of anaphylaxis to PEG,he was stabilized with fluid hydration and continuous norepinephrine infusion.CONCLUSION While allergic reactions to PEG are rare,they can be life-threatening.Therefore,it is crucial for clinicians to be aware of this possibility and to diagnose and resuscitate patients immediately.

Efficacy and tolerability of high and low-volume bowel preparation compared:A real-life single-blinded large-population study

BACKGROUND Low-volume preparations for colonoscopy have shown similar efficacy compared to high-volume ones in randomized controlled trials(RCT).However,most RCTs do not provide data about clinical outcomes including lesions detection rate.Moreover,real-life comparisons are lacking.AIM To compare efficacy(both in terms of adequate bowel preparation and detection of colorectal lesions)and tolerability of a high-volume(HV:4 L polyethylene glycol,PEG)and a low-volume(LV:2 L PEG plus bisacodyl)bowel preparation in a real-life setting.METHODS Consecutive outpatients referred for colonoscopy were prospectively enrolled between 1 December 2014 and 31 December 2016.Patients could choose either LV or HV preparation,with a day-before schedule for morning colonoscopies and a split-dose for afternoon procedures.Adequate bowel preparation according to Boston Bowel Preparation Scale(BBPS),clinical outcomes including polyp detection rate(PDR),adenoma detection rate(ADR),advanced adenoma detection rate(AADR),sessile/serrated lesion detection rate(SDR)and cancer detection rate and self-reported tolerability of HV and LV were blindly assessed.RESULTS Total 2040 patients were enrolled and 1815(mean age 60.6 years,50.2%men)finally included.LV was chosen by 52%of patients(50.8%of men,54.9%of women).Split-dose schedule was more common with HV(44.7%vs 38.2%,P=0.005).High-definition scopes were used in 33.4%of patients,without difference in the two groups(P=0.605).HV and LV preparations showed similar adequate bowel preparation rates(89.2%vs 86.6%,P=0.098),also considering the two different schedules(HV split-dose 93.8%vs LV split-dose 93.6%,P=1;HV daybefore 85.5%vs LV day-before 82.3%,P=0.182).Mean global BBPS score was higher for HV preparations(7.1±1.7 vs 6.8±1.6,P<0.001).After adjustment for sex,age and indications for colonoscopy,HV preparation resulted higher in PDR[Odds ratio(OR)1.32,95%CI:1.07-1.63,P=0.011]and ADR(OR 1.29,95%CI 1.02–1.63,P=0.038)and comparable to LV in AADR(OR 1.51,95%CI 0.97-2.35,P=0.069),SDR and cancer detection rate.The use of standard-definition colonoscopes was associated to lower PDR(adjusted OR 1.59,95%CI:1.22-2.08,P<0.001),ADR(adjusted OR 1.71,95%CI:1.26–2.30,P<0.001)and AADR(adjusted OR 1.97,95%CI:1.09-3.56,P=0.025)in patients receiving LV preparation.Mean Visual Analogue Scale tolerability scored equally(7,P=0.627)but a≥75%dose intake was more frequent with LV(94.6%vs 92.1%,P=0.003).CONCLUSION In a real-life setting,PEG-based low-volume preparation with bisacodyl showed similar efficacy and tolerability compared to standard HV preparation.However,with higher PDR and ADR,HV should still be considered as the reference standard for clinical trials and the preferred option in screening colonoscopy,especially when colonoscopy is performed with standard resolution imaging.

Cleansing efficacy and safety of bowel preparation protocol using sodium picosulfate/magnesium citrate considering subjective experiences:An observational study

BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety of sodium picosulfate/magnesium citrate and to discuss the patients’experiences due to the procedure.METHODS Subjects hospitalized in the International Medical Center Ward of Peking University International Hospital,Beijing,China,from April 29 to October 29,2020,for whom the colonoscopy was planned,were enrolled.Bowel preparation was performed using sodium picosulfate/magnesium citrate.The effect of bowel cleansing was evaluated according to the Ottawa Bowel Preparation Scale,defecation conditions and adverse reactions were recorded,and the comfort level and subjective satisfaction concerning medication were evaluated by the visual analogue scale/score(VAS).RESULTS The bowel preparation procedure was planned for all patients enrolled,which included 42 males and 22 females.The results showed an average liquid rehydration volume of 3000 mL,an average onset of action for the first dose at 89.04 min,an average number of bowel movements of 4.3 following the first dose,an average onset of action for the second dose at 38.90 min and an average number of bowel movements of 5.0 after the second dose.The total average Ottawa Bowel Preparation Scale score was 3.6,with 93.55%of bowel preparations in the“qualified”and 67.74%in the“excellent”grade.The average VAS score of effect on sleep was 0,and the average VAS score of perianal pain was also 0.The average VAS score for ease of taking and taste perception of the bowel cleanser was 10.Side effects included mild to moderate nausea(15.63%),mild vomiting(4.69%),mild to moderate abdominal pain(7.81%),mild to moderate abdominal distension(20.31%),mild palpitation(7.81%)and mild dizziness(4.69%).CONCLUSION Sodium picosulfate/magnesium citrate is effective and safe for bowel preparation before colonoscopy with high subjective patient acceptance,thus improving overall patient compliance.

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.

The effects of enteral nutrition in the bowel preparation in patients with diabetes mellitus

Objective:The objective of the study was to investigate the effect of enteral nutrients in diabetic patients with fibrocolonoscopy.Materials and Methods:A total of 58 diabetic patients undergoing fibrocolonoscopy from January 2017 to December 2017 were included as the traditional bowel preparation group.The patients took traditional semi‑flow diet and catharsis as intestinal preparation and were given health education.Sixty patients treated with fibrocolonoscopy from July to December in 2018 were included as the enteral nutrition group and received enteral nutrients and catharsis as intestinal preparation and were given modified health education.The incidence of hypoglycemia during intestinal preparation was compared between the two groups.Results:A total of 20(34.48%)patients in the traditional bowel preparation group had hypoglycemia(including asymptomatic hypoglycemia)during bowel preparation,with the total frequency of 40.The blood glucose level fluctuated between 1.7 and 3.9 mmol/L.Only five patients in the enteral nutrition group had hypoglycemia(including asymptomatic hypoglycemia)during bowel preparation.The incidence of hypoglycemia was lower in the enteral nutrition group than that in the traditional bowel preparation group(χ^2=4.937,P=0.026).Conclusion:The enteral nutrients as diet for fibrocolonoscopy bowel preparation and strengthening health education could reduce the incidence of hypoglycemia in patients with diabetes during bowel preparation and ensure patient safety.

Same-day single-dose vs large-volume split-dose regimens of polyethylene glycol for bowel preparation:A systematic review and meta-analysis

BACKGROUND Split-dose regimens(SpDs)of 4 L of polyethylene glycol(PEG)have been established as the“gold standard”for bowel preparation;however,its use is limited by the large volumes of fluids required and sleep disturbance associated with night doses.Meanwhile,the same-day single-dose regimens(SSDs)of PEG has been recommended as an alternative;however,its superiority compared to other regimens is a matter of debate.AIM To compare the efficacy and tolerability between SSDs and large-volume SpDs PEG for bowel preparation.METHODS We searched MEDLINE/PubMed,the Cochrane Library,RCA,EMBASE and Science Citation Index Expanded for randomized trials comparing(2 L/4 L)SSDs to large-volume(4 L/3 L)SpDs PEG-based regimens,regardless of adjuvant laxative use.The pooled analysis of relative risk ratio and mean difference was calculated for bowel cleanliness,sleep disturbance,willingness to repeat the procedure using the same preparation and adverse effects.A random effects model or fixed-effects model was chosen based on heterogeneity analysis among studies.RESULTS A total of 18 studies were included.There was no statistically significant difference of adequate bowel preparation(relative risk=0.97;95%CI:0.92-1.02)(14 trials),right colon Boston Bowel Preparation Scale(mean difference=0.00;95%CI:-0.04,0.03)(9 trials)and right colon Ottawa Bowel Preparation Scale(mean difference=0.04;95%CI:-0.27,0.34)(5 trials)between(2 L/4 L)SSDs and large-volume(4 L/3 L)SpDs,regardless of adjuvant laxative use.The pooled analysis favored the use of SSDs with less sleep disturbance(relative risk=0.52;95%CI:0.40,0.68)and lower incidence of abdominal pain(relative risk=0.75;95%CI:0.62,0.90).During subgroup analysis,patients that received low-volume(2 L)SSDs showed more willingness to repeat the procedure using the same preparation than SpDs(P<0.05).No significant difference in adverse effects,including nausea,vomiting and bloating,was found between the two arms(P>0.05).CONCLUSION Regardless of adjuvant laxative use,the(2 L/4 L)SSD PEG-based arm was considered equal or better than the large-volume(≥3 L)SpDs PEG regimen in terms of bowel cleanliness and tolerability.Patients that received low-volume(2 L)SSDs showed more willingness to repeat the procedure using the same preparation due to the low-volume fluid requirement and less sleep disturbance.

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.

Constipation and colonoscopy

Constipation is a significant sociomedical problem,which can be caused by various reasons.In the diagnostic approach to patients with constipation,the following data are usually sufficient:History,complete physical examination(including rectal examination),and additional diagnostic tests.A colonoscopy is not a necessary diagnostic method for all patients with constipation.However,if patients have alarm symptoms/signs,that suggest an organic reason for constipation,a colonoscopy is necessary.The most important alarm symptoms/signs are age>50 years,gastrointestinal bleeding,new-onset constipation,a palpable mass in the abdomen and rectum,weight loss,anemia,inflammatory bowel disease,and family history positive for colorectal cancer.Most endoscopists do not like to deal with patients with constipation.There are two reasons for this,namely the difficulty of endoscopy and the adequacy of preparation.Both are adversely affected by constipation.To improve the quality of colonoscopy in these patients,good examination techniques and often more extensive preparation are necessary.Good colonoscopy technique implies adequate psychological preparation of the patient,careful insertion of the endoscope with minimal insufflation,and early detection and resolution of loops.Bowel preparation for colonoscopy often requires prolonged preparation and sometimes the addition of other laxatives.

Noninferiority clinical trial comparing the bowel cleansing efficacy of sodium phosphate tablets(Quiklean®)with a polyethylene glycol/bisacodyl kit

BACKGROUND Efficient bowel cleansing is essential for a successful colonoscopy,but the ideal cleansing agent,volume,and pharmaceutical dosage form have yet to be determined.Small-volume cleansers enhance patient compliance.AIM To compare the bowel cleansing efficacy of 32-tablet sodium phosphate(Quiklean®)with 2-L polyethylene glycol(PEG)/bisacodyl(Klean-Prep/Dulcolax®)under identical dietary recommendations.METHODS This multicenter,randomized,parallel-group,noninferiority clinical trial enrolled 472 outpatients,randomized 456 subjects,and scheduled 442 subjects to undergo colonoscopy(Quiklean®=222 and Klean-Prep/Dulcolax®=220).After bowel preparation,a colonoscopist performed the colonoscopy with video recorded for rating.The primary efficacy endpoint was the bowel cleansing quality using the Aronchick Scale.The secondary endpoints were the bowel cleansing efficacy of three colon segments,tolerability and acceptability,safety using the Ottawa bowel preparation scale,questionnaires by subjects,and monitoring of adverse events.RESULTS Success rates(Excellent+Good)of the bowel cleansing quality by Aronchick Scale were 98.6%(n=205)and 97.6%(n=204)in the Quiklean®and Klean-Prep/Dulcolax®groups,respectively.Quiklean®demonstrated noninferiority over Klean-Prep/Dulcolax®in colon cleansing efficacy.Quicken showed better tolerability and acceptability in the overall experience(was rated as excellent;24.0%vs 17.2%;P=0.0016)and the taste of the study preparation(was rated as excellent,23.1%vs 13.4%;P<0.0001)than Klean-Prep/Dulcolax®.Safety profiles did not differ between the two groups.Our data indicate that Quiklean®is an adequate,well-tolerated bowel cleansing preparation compared with the standard comparator Klean-Prep/Dulcolax®.CONCLUSION Quiklean®is sodium phosphate tablets available on Taiwan’s market for bowel preparation;it potentially offers patients an alternative to standard large-volume bowel preparation regimens and may,therefore,increase positive attitudes toward colonoscopies and participation rates.

Impact of simethicone on bowel cleansing during colonoscopy in Chinese patients

BACKGROUND Four-liter polyethylene glycol(PEG)solutions are effective for bowel cleansing,but their large volume might hinder patient compliance.Due to the unique features of Asians,4 L PEG might be a suboptimal bowel preparation in predominantly ethnically Asian countries.In view of this,a balance should be achieved between the volume and effectiveness.The ideal bowel cleansing regimen for a colonoscopy has yet to be determined in a Chinese population.AIM To compare the cleansing efficacy of 3 L PEG plus simethicone with 4 L PEG.METHODS A total of 291 patients were randomly allocated to two groups:Group 1(n=145)received 4 L split-dose PEG(4-P);group 2(n=146)received 3 L split-dose PEG plus simethicone(3-PS).Bowel-cleansing efficacy was evaluated by endoscopists using the Boston bowel preparation scale(BBPS)and the bubbles score.RESULTS Although there were no significant differences in the total BBPS score or the adequate rate of bowel preparation between the two groups,the BBPS score of the right-side colon was significantly higher in the 3-SP group(2.37±0.54 vs 2.21±0.78;P=0.04).Moreover,the use of simethicone significantly reduced bubbles in all colon segments(P<0.001).The mean withdrawal time was significantly shorter in the 3-PS group(8.8±3.4 vs 9.6±2.3;P=0.02).Furthermore,significantly more proximal adenomas were detected in the 3-PS group(53.6%vs 45.7%;P=0.03).In addition,the proportions of patients with nausea and bloating were significantly lower in the 3-SP group(P<0.01 for both).More patients in the 3-PS group expressed willingness to repeat the bowel preparation(87.7%vs 76.6%,P=0.01).CONCLUSION Three-liter PEG shows satisfactory bowel cleansing despite the decrease in dosage,and addition of simethicone with better bubble elimination and enhanced patient acceptance offers excellent potential impact on the detection of proximal adenomas in Chinese patients.

Novel frontiers of agents for bowel cleansing for colonoscopy

The incidence of colorectal cancer(CRC)is characterized by rapid declines in the wake of widespread screening.Colonoscopy is the gold standard for CRC screening,but its accuracy is related to high quality of bowel preparation(BP).In this review,we aimed to summarized the current strategy to increase bowel cleansing before colonoscopy.Newly bowel cleansing agents were developed with the same efficacy of previous agent but requiring less amount of liquid to improve patients’acceptability.The role of the diet before colonoscopy was also changed,as well the contribution of educational intervention and the use of adjunctive drugs to improve patients’tolerance and/or quality of BP.The review also described BP in special situations,as lower gastrointestinal bleeding,elderly people,patients with chronic kidney disease,patients with inflammatory bowel disease,patients with congestive heart failure,inpatient,patient with previous bowel resection,pregnant/lactating patients.The review underlined the quality of BP should be described using a validate scale in colonoscopy report and it explored the available scales.Finally,the review explored the possible contribution of bowel cleansing in post-colonoscopy syndrome that can be related by a transient alteration of gut microbiota.Moreover,the study underlined several points needed to further investigations.

Effectiveness of very low-volume preparation for colonoscopy:A prospective, multicenter observational study

BACKGROUND The effectiveness of colonoscopy strictly depends on adequate bowel cleansing.Recently,a 1 L polyethylene glycol plus ascorbate(PEG-ASC)solution(Plenvu;Norgine,Harefield,United Kingdom)has been introduced on the evidence of three phase-3 randomized controlled trials,but it had never been tested in the real-life.AIM To assess the effectiveness and tolerability of the 1 L preparation compared to 4 L and 2 L-PEG solutions in a real-life setting.METHODS All patients undergoing a screening or diagnostic colonoscopy after a 4,2 or 1 L PEG preparation,were consecutively enrolled in 5 Italian centers from September 2018 to February 2019.The primary endpoints of the study were the assessment of bowel cleansing success and high-quality cleansing of the right colon.The secondary endpoints were the evaluation of tolerability,adherence and safety of the different bowel preparations.Bowel cleansing was assessed through the Boston Bowel Preparation Scale.Adherence was defined as consumption of at least 75%of each dose,while tolerability was evaluated through a semiquantitative scale.Safety was systematically monitored through adverse events reporting.RESULTS Overall,1289 met the inclusion criteria and were enrolled in the study.Of these,490 patients performed a 4 L-PEG preparation(Selgesse^■),566 a 2 L-PEG cleansing(Moviprep^■or Clensia^■)and 233 a 1 L-PEG preparation(Plenvu^■).Bowel cleansing by Boston Bowel Preparation Scale was 6.5±1.5 overall and 6.3±1.5,6.2±1.5,7.3±1.5(P<0.001)in the subgroups of 4 L,2 L and 1 L-PEG preparation,respectively.Cleansing success was achieved in 72.4%,74.1%and 90.1%(P<0.001),while a high-quality cleansing of the right colon in 15.9%,12.0%and 41.4%(P<0.001)for 4 L,2 L and 1 L-PEG preparation groups,respectively.The 1 L preparation was the most tolerated compared to the 2 and 4 L-PEG solutions in the absence of serious adverse events within any of the three groups.Multiple regression models confirmed 1 L PEG-ASC preparation as an independent predictor of overall cleansing success,high-quality cleansing of the right colon and of tolerability.CONCLUSION This study supports the effectiveness and tolerability of 1 L PEG-ASC,also showing it is an independent predictor of overall cleansing success,high-quality cleansing of the right colon and of tolerability.

Prospective single-blinded single-center randomized controlled trial of Prep Kit-C and Moviprep:Does underlying inflammatory bowel disease impact tolerability and efficacy?

BACKGROUND Colonoscopy remains the gold standard for detection of colonic disease.An optimal evaluation depends on adequate bowel cleansing.Patients with inflammatory bowel disease(IBD),require frequent endoscopic assessment for both activity and dysplasia assessment.Two commonly used bowel preparations in Australia are Prep Kit-C(Pc)and Moviprep(Mp).Little is known about tolerability,efficacy and safety of split protocols of Mp and Pc in both IBD and non-IBD patients.AIM To primary aim was to compare the tolerability,efficacy and safety of split protocols of Mp and Pc in patients having a colonoscopy.The secondary aim was to compare the efficacy,tolerability and safety of either preparation in patients with or without IBD.METHODS Patients were randomized to Pc or Mp bowel preparation.Patients completed a questionnaire to assess tolerability.Efficacy was assessed using the Ottawa Bowel Preparation Score.Serum electrolytes and renal function were collected one week prior to colonoscopy and on the day of colonoscopy.RESULTS Of 338 patients met the inclusion criteria.Of 168 patients randomized to Mp and 170 to Pc.The efficacy of bowel preparation(mean Ottawa Bowel Preparation Score)was similar between Mp(5.4±2.4)and Pc(5.1±2.1)(P=0.3).Mean tolerability scores were similar in Mp(11.84±5.4)and Pc(10.99±5.2;P=0.17).125 patients had IBD(73 had Crohn’s Disease and 52 had Ulcerative colitis).Sixtyfour IBD patients were allocated to Mp and 61 to Pc.In non-IBD patients,104 were allocated to Mp and 109 to Pc.The mean tolerability score in the IBD group was lower than the non-IBD group(mean tolerability scores:IBD:10.3±5.1 and non-IBD:12.0±5.3;P=0.01).IBD patients described more abdominal pain with Mp when compared with Pc;(Mp:5.7±4.4 vs Pc:3.6±2.6,P=0.046).Serum magnesium level increased with Pc compared with Mp in all patients(mean increase in mmol/L:Mp:0.03±0.117 and Pc:0.11±0.106;P<0.0001).CONCLUSION In this study,the efficacy,tolerability and safety of Mp and Pc were similar in all patients.However,patients with IBD reported lower tolerability with both preparations.Specifically,IBD patients had more abdominal pain with Mp.These results should be considered when recommending bowel preparation especially to IBD patients.

Castor oil as booster for colon capsule endoscopy preparation reduction: A prospective pilot study and patient questionnaire

BACKGROUND Preparation for colon capsule endoscopy(CCE)requires a large liquid laxative volume for capsule excretion,which compromises the procedure's tolerability.AIM To assess the safety and utility of castor oil-boosted bowel preparation.METHODS This prospective cohort study including 20 patients(age range,16-80 years;six men and 14 women)suspected of having colorectal disease was conducted at Kindai University Hospital from September 2017 to August 2019.All patients underwent CCE because of the following inclusion criteria:previous incomplete colonoscopy in other facility(n=20),history of abdominal surgery(n=7),or organ abnormalities such as multiple diverticulum(n=4)and adhesion after surgery(n=6).The exclusion criteria were as follows:Dysphagia,history of allergic reactions to the drugs used in this study(magnesium citrate,polyethylene glycol,metoclopramide,and castor oil),possibility of pregnancy,possibility of bowel obstruction or stenosis based on symptoms,or scheduled magnetic resonance imaging within 2 wk after CCE.The primary outcome was the capsule excretion rate within the battery life,as evaluated by the total large bowel observation rate,large bowel transit time,and bowel creasing level using a fivegrade scale in different colorectal segments.The secondary outcomes were complications,colorectal lesion detection rates,and patients’tolerability.RESULTS The castor oil-based regimen was implemented in 17 patients.Three patients cancelled CCE because they could tolerate castor oil,but not liquid laxatives.The capsule excretion rate within the battery life was 88%(15/17).The mean large bowel transit time was 236 min.Approximately 70%of patients had satisfactory colon cleansing levels.CCE detected colon polyps(14/17,82%)and colonic diverticulum(4/12,33%).The sensitivity,specificity,and diagnostic accuracy rates for detecting colorectal polyps(size≥6 mm)were 76.9%,75.0%,and 76.4%,respectively.The sensitivity,specificity,and diagnostic accuracy rates for detection of diverticulum were 100%each.Twelve patients(71%)rated CCE as more than“good”,confirming the new regimen’s tolerability.No serious adverse events occurred during this study.CONCLUSION The castor oil-based regimen could reduce bowel preparation dose and improve CCE tolerability.

Advancements in AI Research for Digestive System Diseases

With the “boom” of AI, researchers have made significant progress in assisting clinical disease diagnosis, prediction, and treatment. This article provides an overview of models built using both traditional machine learning methods and deep learning methods, as well as research progress on robotics in digestive system diseases, aiming to provide references for further studies. An application has been developed by domestic and foreign scholars that allows users to upload images of stool samples, which are then analyzed using big data to provide a score for bowel preparation, thereby improving the quality of bowel preparation. In some gastrointestinal diseases, such as Hp infection, Barrett’s esophagus and esophageal cancer, chronic atrophic gastritis and gastric cancer, IBD, etc., artificial intelligence possesses diagnostic capabilities comparable to those of professional endoscopists, and some applications can achieve real-time diagnosis. In the field of liver, gallbladder, and pancreatic diseases, artificial intelligence can assist in preoperative diagnosis using imaging or pathology, and robotic remote operations can be performed during surgery, predicting postoperative risk levels, and more. Different scholars have compared and analyzed various algorithm networks for different diseases to find the best-performing models. On this basis, methods such as the MCA attention mechanism, feature selection, gradient descent, and ensemble models can be introduced to further improve the diagnostic performance of the models. In the future, AI can not only help patients self-manage single or multiple diseases, monitor and manage their own diseases in a standardized and reasonable manner, but also predict and treat digestive system diseases at the genetic level.