Gut Lavage Solutions Research Articles

Rectal effluent as a research tool.

Studies of localized secretions are generally superior to those of blood because they contain higher concentrations of molecules specific to the organ of interest. A common method used to analyze localized secretions is lavage. The flow of fluid over the lining of a cavity picks up both cells and soluble factors, and the effluent can be collected for study. Gastrointestinal (GI) lavage is easily and noninvasively performed by the administration of gut lavage solutions such as those routinely given to patients prior to colonoscopy, with GI lavage fluid being the copious, watery rectal effluent subsequently induced. Residual effluent is currently suctioned from the colon and discarded during colonoscopy. With millions of routine colonoscopies performed per year, GI lavage fluid is a rich and largely untapped resource for basic and clinical research. Rectal effluent can also be easily collected in a toilet receptacle without need for a colonoscopy. Rectal effluent generated in this manner has been used to study diarrheal disease, mucosal immunology, inflammatory bowel disease, celiac disease, and cancer. It is often referred to as gut lavage, colon lavage, GI lavage, or whole gut lavage fluid, which makes it challenging to locate previous studies in the literature and there are currently no comprehensive reviews of its use as a research tool. This review attempts to fill this void by discussing previous applications of rectal effluent in research and the methods that have been developed for its collection, stabilization, and analysis.

A meta-analysis of randomized controlled trials of low-volume polyethylene glycol plus ascorbic acid versus standard-volume polyethylene glycol solution as bowel preparations for colonoscopy.

BackgroundStandard-volume polyethylene glycol (PEG) gut lavage solutions are safe and effective, but they require the consumption of large volumes of fluid. A new lower-volume solution of PEG plus ascorbic acid has been used recently as a preparation for colonoscopy.AimA meta-analysis was performed to compare the performance of low-volume PEG plus ascorbic acid with standard-volume PEG as bowel preparation for colonoscopy.StudyElectronic and manual searches were performed to identify randomized controlled trials (RCTs) that compared the performance of low-volume PEG plus ascorbic acid with standard-volume PEG as bowel preparation for colonoscopy. After a methodological quality assessment and data extraction, the pooled estimates of bowel preparation efficacy during bowel cleansing, compliance with preparation, willingness to repeat the same preparation, and the side effects were calculated. We calculated pooled estimates of odds ratios (OR) by fixed- and/or random-effects models. We also assessed heterogeneity among studies and the publication bias.ResultsEleven RCTs were identified for analysis. The pooled OR for preparation efficacy during bowel cleansing and for compliance with preparation for low-volume PEG plus ascorbic acid were 1.08 (95% CI = 0.98–1.28, P = 0.34) and 2.23 (95% CI = 1.67–2.98, P<0.00001), respectively, compared with those for standard-volume PEG. The side effects of vomiting and nausea for low-volume PEG plus ascorbic acid were reduced relative to standard-volume PEG. There was no significant publication bias, according to a funnel plot.ConclusionsLow-volume PEG plus ascorbic acid gut lavage achieved non-inferior efficacy for bowel cleansing, is more acceptable to patients, and has fewer side effects than standard-volume PEG as a bowel preparation method for colonoscopy.

A Comparison of 2 L of Polyethylene Glycol and 45 mL of Sodium Phosphate versus 4 L of Polyethylene Glycol for Bowel Cleansing: A Prospective Randomized Trial

Background/AimsPolyethylene glycol (PEG)-based gut lavage solutions are safe and effective, but require the intake of large volumes of fluid. The use of 2 L PEG plus 45 mL sodium phosphate (PEG2 plus NaP) was compared with 4 L PEG (PEG4) for bowel cleansing before colonoscopy.MethodsPatients were randomized to the PEG2 plus NaP group or PEG4 group between January 1, 2009 and March 31, 2010. One hundred and thirty patients were included in the PEG2 plus NaP group, and 141 patients in the PEG4 group.ResultsThe qualities of the bowel preparation, based on the Ottawa scale were not significantly different between the groups (4.8±2.25 for the PEG2 plus NaP group vs. 5.11±2.26 for the PEG4). In addition, there were no significant differences in side effects. Laboratory findings after bowel preparation, including electrolyte, phosphorus and creatinine levels, were within the normal ranges in both groups.ConclusionsPEG2 plus NaP provides good cleansing that is similar to PEG4, but with a lower volume. However, because PEG2 plus NaP can cause serious side effects such as calcium deposition in the kidneys (i.e., nephrocalcinosis), this solution might be considered for the outpatients who cannot tolerate PEG4.

Update on Preparation for Colonoscopy

Colonoscopy requires adequate bowel cleansing to be safe and effective. Current options for preparation include dietary restrictions plus cathartics and purgatives, large-volume gut lavage solutions, and sodium phosphate preparations. Gut lavage with or without a stimulant laxative is safe and effective, and traditionally is taken the evening before the procedure. Sodium phosphate formulations also provide effective cleansing, but fluid and electrolyte disturbances can occur. Recent advances include split administration of gut lavage solutions-ingesting only half of the solution the evening prior to, and the rest the morning of, the procedure. Split administration can yield adequate preparations in inpatients, traditionally a difficult group for proper cleansing. A new oral sulfate solution, when commercially available, should provide safe, effective cleaning with a lower ingested volume. This review discusses the current clinical experience of available preparation options and the efforts to make preparation for colonoscopy more tolerable.

Randomized Trial of Low-Volume PEG Solution Versus Standard PEG + Electrolytes for Bowel Cleansing Before Colonoscopy

Polyethylene glycol (PEG)-based gut lavage solutions are safe and effective, but require consumption of large volumes of fluid. We compared a new 2 L solution of PEG plus ascorbic acid (PEG + Asc) with standard 4 L PEG with electrolytes (PEG + E) for bowel cleansing before colonoscopy to determine efficacy, safety, and patient acceptability. Consenting adult inpatients scheduled to undergo colonoscopy were randomized to receive either 2 L PEG + Asc or 4 L PEG + E. Preparations were taken as split doses the evening before colonoscopy and the following morning. The PEG + Asc group took 1 L at each administration (i.e., total dose of 2 L). The PEG + E group took 2 L at each administration (i.e., total dose of 4 L). Bowel cleansing success was assessed via videotapes by independent, blinded raters. Statistical noninferiority was predefined as a difference of <15% in the lower limit of the 97.5% confidence interval for treatment difference. Patient views on the preparations were elicited. Adverse events were noted. Successful gut cleansing was achieved in 136 of 153 (88.9%) cases of the PEG + Asc group and 147 of 155 (94.8%) cases of the 4 L PEG + E group (mean difference -5.9 [-12.0-infinity]). The difference fell within the predefined limit for noninferiority. Clinical and laboratory parameters showed no difference in safety profile. Patient ratings of acceptability and taste were better for the PEG + Asc group than for the PEG + E group (P < 0.025). The combination of ascorbic acid and PEG-based bowel preparation reduces the volume patients have to drink without compromising efficacy or safety. The low-volume PEG + Asc preparation was more acceptable to patients, and should, therefore, improve effectiveness in routine practice.

Clinical trial: an efficacy evaluation of reduced bisacodyl given as part of a polyethylene glycol electrolyte solution preparation prior to colonoscopy

In an attempt to further improve patient preparation experience with reduced volume gut lavage solutions using 2-L sulphate-free electrolyte lavage solution plus 20-mg bisacodyl (HalfLytely with Bisacodyl Tablets Bowel Prep Kit, Braintree Laboratories, Inc., Braintree, MA, USA), a low bisacodyl dose preparation was developed using 10 mg bisacodyl. To compare preparation methods using the 10- or 20-mg bisacodyl with 2-L sulphate-free electrolyte lavage method. At 10 US centres, 455 patients undergoing colonoscopy for routine clinical indications were equally randomized to receive 10- or 20-mg bisacodyl with 2-L sulphate-free electrolyte lavage method. Colonoscopists rated the efficacy of colon cleansing, blinded to the preparation assignment. Physician assessment of colon cleansing showed no difference between those randomized to receive the 10- or 20-mg bisacodyl preparations (P = 0.52). The 10-mg preparation had lower symptom scores for cramping (P < 0.001) and overall discomfort (P = 0.001). Other reported adverse experiences were few, mild and not different between groups. Two-litre sulphate-free electrolyte lavage method solution with 10-mg bisacodyl is as effective as the 20-mg bisacodyl preparation for cleansing the colon prior to colonoscopy. The 10-mg bisacodyl regimen has an improved safety profile, with significantly reduced cramping, nausea and overall discomfort.

Safety and Biological Tolerability of a New 2-Litre Gut Cleansing Solution Containing PEG+E in Patient Risk Groups Undergoing Colonoscopy

Aim: To demonstrate that a new oral 2L gut cleansing solution PEG+E plus ascorbate (2L PEG+E) is as safe and well tolerated as the standard 4L PEG+E bowel preparation in risk group patients undergoing colonoscopy. Methods: A randomised, single-blind, multicentre study with two parallel treatment groups (2L PEG+E/Sol.A versus 4L standard PEG+E/Sol.B) included inpatients (aged: 18-85 years) undergoing routine colonoscopy. Both gut lavage solutions were taken as half the dose the evening before followed by the other half on the morning of the colonoscopy. Several subgroups were included: elderly, patients with inflammatory bowel disease (IBD), patients with concomitant cardiovascular (CV) disease and patients with impaired kidney function (creatinine clearance <80 mL/min). The laboratory results were summarised for changes from baseline or clinical significance. Endpoints of the analysis were the rate of adverse events, biological safety, patient acceptance and tolerance in relation to the observed gut cleansing quality. Results: 359 inpatients (180 with Sol.A and 179 with Sol.B) were included in the study. 87 patients (36 with Sol.A/51 with Sol.B) had an age between 65 and 75 years and 53 patients (26 with Sol.A/27 with Sol.B) an age above 75 years. 26 patients (17 with Sol.A/9 with Sol.B) had IBD, 75 patients (41 with Sol.A/34 with Sol.B) had a concomitant CV disease and 147 patients (68 Sol.A/79 Sol.B) an impaired kidney function. None of the risk factors, including age, concomitant CV disease and/or impaired renal function influenced the rate of effective gut cleansing. The observed frequency of adverse events was not different from the gereral population or the established safety profile of standard PEG+E. No clinically relevant differences were observed for the laboratory results. In terms of patient satisfaction, acceptability and taste, patients consistently preferred Sol.A over Sol.B., independent of the presence of risk factors. Similarly, the rating for “no problem” to drink the entire gut cleansing solution was in favour of the 2L Sol.A without any effects of age, CV conditions or impaired kidney function. Conclusion: The analysis has confirmed that the new 2L PEG+E solution is as safe as the well established 4-litre PEG+E solution, including patient subgroups with risk factors, undergoing routine colonoscopies. All patient groups can be prepared with the improved 2L PEG+E solution to enhance the patient acceptance for the colonoscopy procedure. Aim: To demonstrate that a new oral 2L gut cleansing solution PEG+E plus ascorbate (2L PEG+E) is as safe and well tolerated as the standard 4L PEG+E bowel preparation in risk group patients undergoing colonoscopy. Methods: A randomised, single-blind, multicentre study with two parallel treatment groups (2L PEG+E/Sol.A versus 4L standard PEG+E/Sol.B) included inpatients (aged: 18-85 years) undergoing routine colonoscopy. Both gut lavage solutions were taken as half the dose the evening before followed by the other half on the morning of the colonoscopy. Several subgroups were included: elderly, patients with inflammatory bowel disease (IBD), patients with concomitant cardiovascular (CV) disease and patients with impaired kidney function (creatinine clearance <80 mL/min). The laboratory results were summarised for changes from baseline or clinical significance. Endpoints of the analysis were the rate of adverse events, biological safety, patient acceptance and tolerance in relation to the observed gut cleansing quality. Results: 359 inpatients (180 with Sol.A and 179 with Sol.B) were included in the study. 87 patients (36 with Sol.A/51 with Sol.B) had an age between 65 and 75 years and 53 patients (26 with Sol.A/27 with Sol.B) an age above 75 years. 26 patients (17 with Sol.A/9 with Sol.B) had IBD, 75 patients (41 with Sol.A/34 with Sol.B) had a concomitant CV disease and 147 patients (68 Sol.A/79 Sol.B) an impaired kidney function. None of the risk factors, including age, concomitant CV disease and/or impaired renal function influenced the rate of effective gut cleansing. The observed frequency of adverse events was not different from the gereral population or the established safety profile of standard PEG+E. No clinically relevant differences were observed for the laboratory results. In terms of patient satisfaction, acceptability and taste, patients consistently preferred Sol.A over Sol.B., independent of the presence of risk factors. Similarly, the rating for “no problem” to drink the entire gut cleansing solution was in favour of the 2L Sol.A without any effects of age, CV conditions or impaired kidney function. Conclusion: The analysis has confirmed that the new 2L PEG+E solution is as safe as the well established 4-litre PEG+E solution, including patient subgroups with risk factors, undergoing routine colonoscopies. All patient groups can be prepared with the improved 2L PEG+E solution to enhance the patient acceptance for the colonoscopy procedure.

Bowel preparation for gastrointestinal procedures.

Adequate colonic cleansing is essential for accurate and safe colonic procedures. Common preparations for cleansing include diet in combination with a cathartic agent, gut lavage, and phosphate preparations. The diet used with a cathartic consists of clear liquids or is designed to leave a minimal colonic fecal residue with laxatives. Gut lavage solutions wash out the colon in a safe and effective manner. Phosphate preparations offer an attractive alternative due to smaller volumes required for ingestion; however, electrolyte disturbances can occur. This review discusses the development and clinical experience with various colon cleansing regimens and efforts to improve the tolerability and safety of preparation for colonoscopy, virtual colonoscopy, colon surgery, barium enema, and flexible sigmoidoscopy.

Results of a Randomised, Multi-Centre, Single-Blind Trial to Compare the Efficacy, Acceptability and Safety of a New 2-Litre Gut Cleansing Solution Versus a Standard 4-Litre PEG+E Solution

*S1555 Results of a Randomised, Multi-Centre, Single-Blind Trial to Compare the Efficacy, Acceptability and Safety of a New 2-Litre Gut Cleansing Solution Versus a Standard 4-Litre PEG+E Solution Christian Ell, Hans-Juergen Gruss AIM:Todemonstrate that aneworal gut cleansing solutionNRL994 is as effectiveas the existing polyethylene glycol 3350 plus electrolytes (PEG+E) solution as a bowel preparation prior to colonoscopy. METHODS: The study was carried out as a randomised, single-blind, active-controlled, multi-centre study with two parallel treatment groups. Only patients (aged: 18-85 years) scheduled to undergo routine colonoscopy without history of colonic surgery, presence of colonic obstruction/ perforation of the colon, severe cardiovascular conditions and terminal kidney or liver diseases were eligible. Both gut lavage solutions were taken as half dose the eveningbefore followedbytheotherhalf onthemorningof thecolonoscopy.Primary efficacy criteria was the gut cleansing quality, as judged by a blinded expert panel on the basis of videotapes. Secondary endpoints were the degree of gut cleansing in predefined gut segments, overall gut cleansing, evaluation of taste, patient’s satisfaction and acceptability and a full safety assessment. RESULTS: A total of 359 patients (180 with NRL994 and 179 with PEG+E) in 12 centres received study medication. 9 patients withdrew during the study. 42 cases were major protocol violators, mainly related to the absence of a videotape recording. Therefore, 308 patients (153 with NRL994 and 155 with PEG+E) were analysed for the primary efficacy endpoint. The overall success rate was 88.9% in the NRL994 group and 94.8% in thePEG+Egroup.NRL994 is as effective as PEG+E.Themean scores of gut cleansingwere 2.5+/ 0.5 in theNRL994groupand2.5+/ 0.4 in thePEG+E group. Patients consistently preferredNRL994 overPEG+E, assessedby the degree of patient satisfaction, overall acceptability of the gut cleansing solution and taste assessment. Both treatments were well tolerated and had similar adverse event profileswith frequentmild treatment-relatedmalaise, nausea, unspecifiedabdominal pain and vomiting. No relevant shifts in the laboratory tests were observed. CONCLUSION: The study has shown that the new 2 litre NRL994 gut lavage solution proved to be as effective as the existing 4-litre PEG+E solution. Patients consistently preferred NRL994 to PEG+E. Both treatments proved to be safe and generally well tolerated. This new lower volume bowel cleansing solution provides abetterpatientacceptabilitywithout any lossof efficacyor enhanced safety concerns. Comparison of Endoscopic Experience Obtained in an American and a British Gastroenterology Training Program Sean Weaver, Sanjib Mohanty, David Fine, Paul Winwood, Kim Isaacs, Ian Grimm Introduction: Endoscopy represents a central part of gastroenterology training but very little is known about the experience gained in training. The recommendations for endoscopic experience by the ASGE, and the joint advisory group (JAG) for endoscopy in Britian, suggest a relatively low volume of experience to become competent. Three year American programs are shorter than British training which has a minimum of four dedicated years. However many British trainees do more and intercalate a higher research degree. There have been concerns that if the intensity and length of British training are shortened then endoscopic training will suffer. Methods: The records of endoscopic experience from 11 trainees completing the gastroenterology program at the University of North Carolina at Chapel Hill were compared with 9 trainees within one year of completion of training in the British region of Wessex. Results: American and British trainees significantly exceeded both British and American recommendations for experience in both upper and lower gastrointestinal endoscopy. British trainess carried out significantly more upper gastrointestinal endoscopy (mean 2429 vs 662 p<0.05; ASGE recommendation 130; JAG guideline 300) and tended to carry out more colonoscopy (mean 664 vs 483 ns; ASGE recommendation 140; JAG guideline 200). The recommendation of 200 ERCP procedures was only reached by some trainees in both America (3/11; mean 172) and Britain (7/8; mean 198). All procedures in America were supervised by a trainer. In Britain supervision was often indirect once competence was demonstrated. Conclusions: In both training programs trainees get extensive experience in both upper and lower gastrointestinal endoscopy. Obtaining appropriate experience in ERCP is not always achieved which has resulted in some programs training only some of its trainees. The reasons why British trainees gain more upper gastrointestinal experience are probably dependent on length of training (including 8/9 having a research degree), differences in endoscopic practice between the two countries, and time spent outside a tertiary referral teaching hospital environment. There is evidence that training in general endoscopy in Britain would be adequate if British training is shortened or made less intense.

Safety Issues Regarding Colonic Cleansing for Diagnostic and Surgical Procedures

There are various methods available to cleanse the colon in preparation for diagnostic and surgical procedures. The popular options are diet and cathartic regimens, gut lavage and phosphate preparations. Each method has its own unique characteristics and safety profile. Diet and cathartic regimens are based on traditional methods of colonoscopy preparation and remain an acceptable and safe alternative for patients unwilling or unable to tolerate other bowel preparations. Gut lavage methods involve ingestion of 2-4L of osmotically balanced solutions containing polyethylene glycol, which have been shown to be safe and effective for colon cleansing, including for special patient populations with cardiac, renal or hepatic dysfunction. Phosphate preparations have also been shown to be safe and effective for colon cleansing and are generally better tolerated than counterpart gut lavage solutions. However, this method has safety concerns for some patients with cardiac, renal and hepatic dysfunctions.

Review article: colon cleansing preparation for gastrointestinal procedures.

Adequate cleansing is essential for reliable diagnostic and surgical colon procedures. Accuracy and safety depend on good preparation. Patient compliance is enhanced by simplicity and well-tolerated methods. Several methods are available. Diet and cathartic regimens utilize clear liquids or diets designed to leave a minimal colonic residue. Laxatives, cathartics and enemas are employed. Gut lavage solutions are osmotically balanced electrolyte lavage products. Oral sodium phosphate solutions and tablets are available and are attractive because of good efficacy with a small volume of administration. For colonoscopy and colon surgery preparation, these methods have been proven safe and effective. For barium enema X-ray, lavage requires an adjunctive agent such as bisacodyl to enhance barium coating. Overall, all regimens are well-tolerated. This review discusses the development and clinical experience with various colon cleansing regimens.

Cytologic detection of colorectal cancer after administration of oral lavage solution

Whether malignant cells can be detected in the bowel movements induced by oral gut lavage solution administration was studied in patients with known colonic adenocarcinomas. The induced bowel movements were collected in 27 patients, nine of whom had cancer proven by anatomic pathologic examination. The cells present were recovered with a simple technique and stained by the Papanicolaou method. Malignant cells were identified in the stained preparations in all nine patients with cancer (100% sensitivity), and there were few false positives (94.5% specificity). The authors concluded that if additional studies with greater numbers of subjects confirm the reliability of this technique, a test may be developed that would be useful for either early detection or screening.

A New Oral Lavage Solution vs Cathartics and Enema Method for Preoperative Colonic Cleansing

Sulfate free-electrolyte lavage solution is a new osmotically balanced electrolyte gut lavage solution for colon surgery that has been formulated for improved taste and reduced water and electrolyte changes. Sixty patients were prospectively randomized to receive a 1-day preparation with sulfate free-electrolyte lavage solution or a 3-day preparation using a clear liquid diet, cathartics, and enemas. The patient groups were similar in age, race, male-female ratio, and the types of colonic resections performed. Colonic cleansing was better with sulfate free-electrolyte lavage solution (100% vs 63% "good" to "excellent" cleansing). Patient tolerance evaluated by a questionnaire showed more overall discomfort with sulfate free-electrolyte lavage solution but no difference between the preparations in individual symptoms of fullness, cramping, nausea, or vomiting. One patient developed a low level of serum potassium after a cathartic and enema preparation, while there were no complications with sulfate free-electrolyte lavage solution. Patient taste questionnaires showed a slight preference for sulfate free-electrolyte lavage solution (53%) over a polyethylene glycol electrolyte lavage solution (47%). This study confirms that sulfate free-electrolyte lavage solution is a safe and effective method of preoperative colonic cleansing.

Bowel cleansing with polyethylene glycol electrolyte lavage solution.

We reviewed our experience with an oral gut lavage solution (GoLYTELY), used as a rapid bowel cleansing preparation, and the prospective clinical trials reported in the literature to compare the overall experience with this type of preparation for colonoscopy and colon surgery. Five studies (546 patients) compared GoLYTELY to standard preparations for colonoscopy, while three trials (177 patients) have studied surgical patients. After evaluating patient tolerance, quality of colonic cleansing, and changes in microflora and colonic gas, GoLYTELY was found to be safe, rapid, and effective. It is well tolerated by patients and may become the preferred method of bowel cleansing.

Evaluation of rapid colonoscopy preparation using a new gut lavage solution

The traditional colonoscopy preparation of laxatives and enemas requires 2 days to complete and is occasionally unsatisfactory. The alternative method, gut lavage with saline-based solutions, is hazardous in elderly or compromised patients because of overhydration. We studied a new, orally ingested electrolyte solution containing sodium sulfate and polyethylene glycol as preparation for elective colonoscopy in a consecutive series of 43 patients. Almost all patients achieved a good to excellent preparation. There were no changes in fluid or electrolyte balance and no complications of the procedure. Colonoscopy preparation with this technique is rapid, effective, and well tolerated and is a safe alternative to the standard approach.