Oral colorectal cleansing preparations in adults

Pre-Operative Mechanical Bowel Preparation Does Not Affect the Impact of Anastomosis Leakage in Left-Side Colorectal Surgery-A Single Center Observational Study

Despite rapid advances in colorectal surgery, morbidity and mortality rates in elective gastrointestinal surgery play a significant role. For decades, there have been tempestuous discussions on preventative measures to minimize the risk of anastomotic dehiscence. When mechanical bowel preparation before an elective procedure, one of the key hypotheses, was introduced into practice, it was assumed that it would decrease the number of infectious complications and anastomotic dehiscence. The advancements in antibiotic treatment supported the concomitant administration of oral antibiotics and mechanical bowel preparation. In the prospective study conducted at our clinic, we performed left-side colorectal procedures without prior mechanical preparation. All patients enrolled in the study underwent the surgery and were observed in the 3rd Surgical Clinic, Faculty of Medicine, Comenius University in Bratislava, Slovakia, from January 2019 to January 2020. As a control group, we used a similar group of patients with MBP. Our observed group included 87 patients with tumors in the left part of their large intestine (lineal flexure, descendent colon, sigmoid colon, and rectum). Dixon laparoscopic resection was performed in 26 patients. Sigmoid laparoscopic resection was performed in 27 patients. In 12 patients, the procedure was started laparoscopically but had to be converted due to adverse anatomical conditions. The conservative approaches mostly included Dixon resections (19 patients), sigmoid colon resections (5 patients), left-side hemicolectomies (6 patients), and Miles' tumor resections, with rectal amputation (4 patients). Our study highlighted the fact that MBP does not have an unequivocal benefit for patients with colorectal infection, which has an impact on the development of anastomotic dehiscence.

Is mechanical bowel preparation necessary to reduce surgical site infection following colon surgery? Protocol for a multicentre Canadian randomized controlled trial

AIM

There is significant practice variation with respect to the use of bowel preparation to reduce surgical site infection (SSI) following colon surgery. Although intravenous antibiotics + mechanical bowel preparation + oral antibiotics (IVA + MBP + OA) has been shown to be superior to IVA + MBP and IVA, there are insufficient high-quality data from randomized controlled trails (RCTs) that directly compare these options. This is an important question, because if IVA + OA has similar effectiveness to IVA + MBP + OA, mechanical bowel preparation can be safely omitted, and the associated side effects avoided. The aim of this work is to compare rates of SSI following IVA + OA + MBP (MBP) versus IVA + OA (OA) for elective colon surgery.

METHOD

This is a multicentre, parallel, two-arm, noninferiority RCT comparing IVA + OA + MBP versus IVA + OA. The primary outcome is the overall rate of SSI 30 days following surgery. Secondary outcomes are length of stay and 30-day emergency room visit and readmission rates. The planned sample size is 1062 subjects with four participating high-volume centres. Overall SSI rates 30 days following surgery between the treatment groups will be compared using a general linear model. Secondary outcomes will be analysed with linear regression for continuous outcomes, logistic regression for binary outcomes and modified Poisson regression for count data.

CONCLUSION

It is expected that IVA + OA will work similarly to IVA + MBP + OA and that this work will provide definitive evidence showing that MBP is not necessary to reduce SSI. This is highly relevant to both patients and physicians as it will have the potential to significantly change practice and outcomes following colon surgery in Canada and beyond.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Systematic review registration

10.37766/inplasy2023.5.0013, identifier: NPLASY202350013.

The safety and effectiveness of 2-liter polyethylene glycol plus ascorbic acid in patients with liver cirrhosis: A retrospective observational study

The safety of bowel-cleansing agents is an important issue in clinical practice, especially in patients with chronic diseases. Although the safety and efficacy of polyethylene glycol (PEG) has been investigated in many studies, few studies on PEG plus ascorbic acid exist. In this study, we compared the safety of 2 bowel-cleansing agents for patients with liver cirrhosis: 2-liter PEG (2 L PEG) plus ascorbic acid versus 4-liter PEG (4 L PEG). We performed a retrospective study on colonoscopy in patients with liver cirrhosis. Patients referred for colonoscopy were divided into 2 groups: 2 L PEG plus ascorbic acid (n = 105) and 4 L PEG (n = 61). Safety was assessed by comparing the clinical factors and laboratory findings as follows: blood biochemistry, electrolytes, weight change, and bowel-cleansing quality. Serum electrolytes, laboratory findings, and body weight showed no significant change between the 2 groups. There was no significant change in clinical factors before and after bowel preparation in the PEG group or the PEG plus ascorbic acid group. The acceptability and compliance of patients was better in the 2 L PEG plus ascorbic acid than the 4 L PEG group. In subgroup analysis, patients with compensated or decompensated cirrhosis showed no increased risk of electrolyte imbalances after bowel preparation. Child-Pugh scores did not influence the outcome after bowel cleansing. Successful cleansing was mostly achieved in both groups. Our analysis showed that of the use of 2 L PEG plus ascorbic acid could be a safe choice for colonoscopy in patients with liver cirrhosis.

Prospective, randomized comparison of same-day dose of 2 different bowel cleanser for afternoon colonoscopy: picosulfate, magnesium oxide, and citric acid versus polyethylene glycol

For afternoon colonoscopy, same-day administration of sodium picosulfate, magnesium oxide, and citric acid (PM/Ca) is recommended. However, few studies have evaluated the bowel-cleansing efficacy and safety of this regimen. The aim of this study was to compare the bowel-cleansing efficacy, side effects, and patient's tolerability of a same-day split administration of PM/Ca with polyethylene glycol (PEG) for afternoon colonoscopy. Patients were randomly assigned to a PM/Ca group or a PEG group. The PM/Ca group consumed 1 sachet of PM/Ca at 06:00 and 1 sachet of PM/Ca 4 hours before the colonoscopy. They also took 2 tablets of bisacodyl before sleep on the night before. The PEG group consumed 2 L of PEG at 06:00 and 2 L of PEG 4 hours before the colonoscopy. All subjects were instructed to finish the bowel cleanser or fluid at least 2 hours before colonoscopy. All colonoscopic examinations were performed in the afternoon on the same day. The bowel-cleansing efficacy was scored using 2 scales: the Ottawa Bowel Preparation Scale (OBPS) and the Aronchick scale. Ease of using the bowel cleanser was rated from 1 (very easy) to 5 (very difficult). Two hundred nine patients underwent colonoscopy. The bowel-cleansing scores by OBPS did not differ between groups (5.0 vs 4.9, P = 0.63). Ease of using the bowel cleanser was superior in the PM/Ca group (P < 0.01). The cleansing efficacy of PM/Ca administered on the day of colonoscopy is comparable to that of PEG. Patients prefer PM/Ca.

Development and validation of the Mayo Clinic Bowel Prep Tolerability Questionnaire

BACKGROUND

Bowel cleansing is paramount for colonoscopy quality. Unfortunately, an adequate bowel preparation is often limited by side effects and/or patient's intolerance to bowel preparation solutions. Comparisons among different preparations are limited by the lack of validated instruments designed to assess patient's tolerability.

AIM

To develop and validate a simple, comprehensive instrument to assess bowel preparation tolerability in patients undergoing colonoscopy.

METHODS

Development and validation by phases: Phase I (bibliographic search and questionnaire design); Phase II (assessment of content validity and modification of the questionnaire); Phase III (assessment of reproducibility, final validation, and definitive version of the questionnaire).

RESULTS

The initial draft of the questionnaire was generated based on a systematic literature review and feedback from a panel of consultants. Content validity was tested in a focus group of 25 patients undergoing colonoscopy. Patients' suggestions were reviewed by the research team and a second draft of the questionnaire was generated. Final validation and reproducibility were successfully tested (agreement: 86-100%, kappa: 0.77-1.00) in a convenience sample of 100 patients undergoing bowel preparation with different cleansing solutions.

CONCLUSION

The Mayo Clinic Bowel Prep Tolerability Questionnaire is a simple, comprehensive instrument suitable to evaluate the tolerability of various types of bowel preparations.

Bowel preparations for colonoscopy: an RCT

BACKGROUND

The ideal preparation regimen for pediatric colonoscopy remains elusive, and available preparations continue to represent a challenge for children. The aim of this study was to compare the efficacy, safety, tolerability, and acceptance of 4 methods of bowel cleansing before colonoscopy in children.

METHODS

This randomized, investigator-blinded, noninferiority trial enrolled all children aged 2 to 18 years undergoing elective colonoscopy in a referral center for pediatric gastroenterology. Patients were randomly assigned to receive polyethylene glycol (PEG) 4000 with simethicon (PEG-ELS group) or PEG-4000 with citrates and simethicone plus bisacodyl (PEG-CS+Bisacodyl group), or PEG 3350 with ascorbic acid (PEG-Asc group), or sodium picosulfate plus magnesium oxide and citric acid (NaPico+MgCit group). Bowel cleansing was evaluated according to the Boston Bowel Preparation Scale. The primary end point was overall colon cleansing. Tolerability, acceptability, and compliance were also evaluated.

RESULTS

Two hundred ninety-nine patients were randomly allocated to the 4 groups. In the per-protocol analysis, PEG-CS+Bisacodyl, PEG-Asc, and NaPico+MgCit were noninferior to PEG-ELS in bowel-cleansing efficacy of both the whole colon (P = .910) and colonic segments. No serious adverse events occurred in any group. Rates of tolerability, acceptability, and compliance were significantly higher in the NaPico+MgCit group.

CONCLUSIONS

Low-volume PEG preparations (PEG-CS+Bisacodyl, PEG-Asc) and NaPico+MgCit are noninferior to PEG-ELS in children, representing an attractive alternative to high-volume regimens in clinical practice. Because of the higher tolerability and acceptability profile, NaPico+MgCit would appear as the most suitable regimen for bowel preparation in children.

A Retrospective Case-Control Study Evaluating the Bowel Preparation Quality during Surveillance Colonoscopy after Colonic Resection

Purpose. Bowel preparation for surveillance endoscopy following surgery can be impaired by suboptimal bowel function. Our study compares two groups of patients in order to evaluate the influence of colorectal resection on bowel preparation. Methods. From April 2010 to December 2011, 351 patients were enrolled in our retrospective study and divided into two homogeneous arms: resection group (RG) and control group. Surgical methods were classified as left hemicolectomy, right hemicolectomy, anterior rectal resection, and double colonic resection. Bowel cleansing was evaluated by nine skilled endoscopists using the Aronchick scale. Results. Among the 161 patients of the RG, surgery was as follows: 60 left hemicolectomies (37%), 62 right hemicolectomies (38%), and 33 anterior rectal resections (20%). Unsatisfactory bowel preparation was significantly higher in resected population (44% versus 12%; P value = 0.000). No significant difference (38% versus 31%, P value = ns) was detected in the intermediate score, which represents a fair quality of bowel preparation. Conclusions. Our study highlights how patients with previous colonic resection are at high risk for a worse bowel preparation. Currently, the intestinal cleansing carried out by 4 L PEG based preparation does not seem to be sufficient to achieve the quality parameters required for the post-resection endoscopic monitoring.

A dual-action, low-volume bowel cleanser administered the day before colonoscopy: results from the SEE CLEAR II study

OBJECTIVES

Optimal bowel preparation is vital for the efficacy and safety of colonoscopy. The inconvenience, discomfort, required consumption of large volumes of product, and potential adverse effects associated with some bowel preparations deter patients from colonoscopy and may provide inadequate cleansing. A dual-action, non-phosphate, natural orange-flavored, low-volume preparation containing sodium picosulfate and magnesium citrate (P/MC) is currently being reviewed for bowel cleansing.

METHODS

This was a phase 3, randomized, multicenter, assessor-blinded, prespecified non-inferiority, head-to-head study to investigate the efficacy, safety, and tolerability of day-before administration of P/MC vs. 2L polyethylene glycol solution and two 5-mg bisacodyl tablets (2L PEG-3350 and bisacodyl tablets (HalfLytely and Bisacodyl Tablets Bowel Prep Kit)) in adult patients preparing for colonoscopy (SEE CLEAR II Study). The primary objective of the study was to demonstrate the non-inferiority of P/MC to 2L PEG-3350 and bisacodyl tablets in overall colon cleansing using a modified Aronchick scale. In addition, efficacy in the ascending, mid (transverse and descending), and recto-sigmoid segments of colon was evaluated using a modified Ottawa scale. Patient acceptability and tolerability of the bowel preparations were assessed via a standard questionnaire. Safety was assessed based on the monitoring of adverse events (AEs) and meaningful findings on clinical evaluations including physical examinations, vital sign measurements, and electrocardiograms (ECGs).

RESULTS

A total of 603 patients were randomized to receive either P/MC (n = 300) or 2L PEG-3350 and bisacodyl tablets (n = 303). Based on the Aronchick scale, successful overall cleansing was similar in patients receiving P/MC (83.0%) and patients receiving 2L PEG-3350 and bisacodyl tablets (79.7%). P/MC demonstrated non-inferiority to 2L PEG-3350 and bisacodyl tablets in overall cleansing of the colon, as measured by the Aronchick scale. Similarly, the efficacy of P/MC, as measured by the Ottawa scale, was non-inferior to 2L PEG-3350 and bisacodyl tablets in cleansing the ascending, mid, and recto-sigmoid segments of the colon. Patient-reported acceptability and tolerability for each item examined on the questionnaire was significantly greater for P/MC compared with 2L PEG-3350 and bisacodyl tablets (P<0.0001).Treatment-emergent AEs related to the bowel preparation reported by 1% of patients receiving P/MC or 2L PEG-3350 and bisacodyl tablets were nausea (3.0% vs. 4.3%), vomiting (1.4% vs. 2.0%), and headache (2.7% vs. 1.7%). No clinically meaningful changes were noted in either treatment arm in data collected from physical examinations, vital sign measurements, and ECGs.

CONCLUSIONS

When administered as a day-before dose, the bowel cleansing effects of P/MC were non-inferior compared with 2L PEG-3350 and bisacodyl tablets using the clinician-rated Aronchick and Ottawa scales. Treatment acceptability was significantly more favorable in patients receiving P/MC than in patients receiving 2L PEG-3350 and bisacodyl tablets.

Colonoscopic enema as rescue for inadequate bowel preparation before colonoscopy: a prospective, observational study

AIM

Colonoscopy may need to be rescheduled because of inadequate bowel preparation. We evaluated the effectiveness of colonoscopic enema as rescue for an inadequate 1-day bowel preparation before colonoscopy.

METHOD

Patients referred for afternoon colonoscopy were prospectively enrolled in the study during a 1-year period. Patients took bowel preparation (polyethylene glycol) solution on the morning of the endoscopy. If during colonoscopy the bowel preparation was poor, an enema of polyethylene glycol solution (500 ml) was instilled into the colon at the level of the hepatic flexure via the biopsy channel of the colonoscope which was then removed. The patient was allowed to recover from the propofol sedation and used the bathroom to evacuate the enema. The colonoscope was then introduced and the examination continued.

RESULTS

Of 504 patients undergoing colonoscopy, 26 (4.9%) received an enema. The median age was 59 (29-79) years and 19 (73%) were female. A subsequent successful colonoscopy was achieved in 25/26 (96%). There were no complications. The mean time spent for the entire colonoscopy from the initial preparation to the end of the examination including the enema was 7.6± 1.1h (5.4 h preparation, 0.2h first colonoscopy+enema, 0.66h waiting in the lavatory, 0.33h second colonoscopy and 1 h for recovery).

CONCLUSION

Colonoscopic enema was highly successful as rescue for patients with inadequate bowel preparation and avoided postponement of the procedure.

A randomized controlled trial evaluating a new 2-L PEG solution plus ascorbic acid vs 4-L PEG for bowel cleansing prior to colonoscopy

BACKGROUND

Bowel preparation is critical for the efficacy and safety of colonoscopy. Poor patient tolerance to bowel preparation has been associated with the high amount of fluid administered. A 2-L polyethylene glycol (PEG) solution containing ascorbic acid has been recently developed.

AIMS

To compare the efficacy, safety and acceptability of 2-L PEG+ascorbic acid vs 4-L PEG for colonoscopy.

METHODS

We designed a single blind randomized non-inferiority study in order to compare the two bowel preparations. A blinded assessment of cleansing was made by the endoscopist according to the Aronchick scale. Acceptability was assessed by questionnaire. Intention-to-treat (ITT) and per-protocol (PP) analysis were reported.

RESULTS

Overall, 169 patients (PP: 166) were selected for the 2-L PEG+ascorbic acid and 170 (PP: 166) for the 4-L PEG. When rating global bowel cleansing at ITT, an excellent-good level was reported in 84.6% (PP: 86.2%) of patients who received 2-L PEG+ascorbic acid and 75.3% (PP: 77%) of patients who received 4-L PEG (p=0.04). Acceptability rate favoured 2-L PEG+ascorbic acid vs 4-L PEG (83% vs 76%; p=0.02).

CONCLUSIONS

2-L PEG+ascorbic acid, completed with an additional L of clear fluids, provided bowel cleansing which appeared to be more effective and acceptable than 4-L PEG.

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 size estimation. 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 + Sim 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.

Preparation before colonoscopy: a randomized controlled trial comparing different regimes

BACKGROUND AND AIM

A good bowel preparation is essential for optimal visualization of the large intestine. Several preparations with a difference in composition and volume are available. We compared five methods for bowel cleansing quality and patients' acceptability.

PATIENTS AND METHODS

Adult ambulatory outpatients scheduled for elective colonoscopy were randomized to receive 4-l polyethylene glycol (PEG) solution (Klean-prep), 2-l PEG solution+ascorbic acid (Moviprep), or a sodium phosphate (NaP) solution, Phosphoral. Patients with the PEG solutions were also randomized to receive simethicone (Aeropax), to investigate whether this improves the bowel cleansing efficacy. Before colonoscopy patients completed a questionnaire about the acceptability and tolerability of the preparation. Endoscopists blinded to the type of preparation gave a bowel cleansing score.

RESULTS

Data were available for 461 patients. 2-l PEG+ascorbic acid was noninferior to 4-l PEG in bowel cleansing quality of rectosigmoid and colon. NaP was noninferior to 4-l PEG in bowel cleansing quality of rectosigmoid but inferior for the whole colon. Compliance was significantly less in the group with 4-l PEG compared with the 2-l PEG and NaP group. No difference was found for abdominal cramps. Taste was significantly better in the 2-l PEG group. Simethicone did not improve the bowel cleansing quality.

CONCLUSION

2-l PEG+ascorbic acid was noninferior to the 4-l PEG solution in bowel cleansing quality and was better in taste and compliance. NaP was inferior to 4-l PEG in bowel cleansing quality. Addition of simethicone gave no improvement.

Mechanism of action and toxicities of purgatives used for colonoscopy preparation

IMPORTANCE OF THE FIELD

In developed countries, colonoscopy volume has increased dramatically over the past 15 years and is the principle method used to screen for colon cancer. Preparations used for colon cleaning have evolved over the past 30 years. Some preparations have been shown to be unsafe and are now used on a limited basis. There has been progress on limiting the volume required and on taste improvement.

AREAS COVERED IN THIS REVIEW

This review provides an account of preparations used from 1980 when PEG-based preparations became widely available, until the present day. The review highlights their mechanism of action and principle toxicities. The handling of solutes and solute-free fluid by the colon is also reviewed.

WHAT THE READER WILL GAIN

The reader will gain a perspective on the factors considered in developing colonic purgatives and the rationale for choosing selected preparations based on patient factors such as age, co-morbidities and concomitant medications.

TAKE HOME MESSAGE

Although generally safe and effective, colonic purgatives have both acute and permanent toxicities. The safest preparations utilize PEG combined with a balanced electrolyte solution. Limitations of this preparation center on the volume required and poor taste. Alternative formulations are now available; however, those using sodium phosphate have fallen out of favor due to a risk of renal toxicity.

Affibody-functionalized gold-silica nanoparticles for Raman molecular imaging of the epidermal growth factor receptor

The affibody functionalization of fluorescent surface-enhanced Raman scattering gold-silica nanoparticles as multimodal contrast agents for molecular imaging specific to epidermal growth factor receptor (EGFR) is reported. This nanoparticle bioconjugate reports EGFR-positive A431 tumors with a signal nearly 35-fold higher than EGFR-negative MDA-435S tumors. The low-level EGFR expression in adjacent healthy tissue is 7-fold lower than in the positive tumors. Validation via competitive inhibition reduces the signal by a factor of six, and independent measurement of EGFR via flow cytometry correlates at R(2) = 0.92.

Clinical trial: 2-L polyethylene glycol-based lavage solutions for colonoscopy preparation - a randomized, single-blind study of two formulations

BACKGROUND

The 2-L polyethylene glycol (PEG) lavage solutions provide efficacy similar to that of standard 4-L PEG formulations in spite of the reduced volume. The comparative efficacy and tolerability of two formulations of 2-L PEG solution remain unknown.

AIMS

To assess the efficacy, safety and tolerability of PEG + Bis compared with PEG + Asc, and to study the effect of bowel cleansing quality on adenoma detection rates.

METHODS

Patients were randomized to receive either 2-L PEG with ascorbic acid (PEG + Asc) or 2-L PEG plus bisacodyl 10 mg (PEG + Bis). The primary endpoint was overall colon cleansing score, assessed by blinded investigators using a validated four-point scale. Secondary endpoints included adenoma detection rate, patient tolerability and compliance and adverse events.

RESULTS

Fifty-two patients received PEG + Asc and 55 patients received PEG + Bis. Overall colon cleansing scores (+/-s.d.) were 1.40 +/- 0.69 and 1.75 +/- 0.70 (P < 0.003) in the PEG + Asc and PEG + Bis groups, respectively. Excellent and good ratings were recorded in 69% and 23% receiving PEG + Asc compared to 38% and 51% (P = 0.01) of patients receiving PEG + Bis. More adenomas were detected in colonoscopies performed with PEG + Asc (39%) than in those performed with PEG + Bis (20%) (P = 0.04). Patient tolerability and safety were similar with both preparations.

CONCLUSION

The use of PEG + Asc resulted in better colon cleansing and higher adenoma detection rates compared with PEG + Bis.

Bowel preparation for pediatric colonoscopy procedures

Colonoscopy is a routinely performed procedure in children and adolescents. Proper visualization of the intestinal mucosa, completion of the procedure, including examination of the terminal ileum, detection of pathological lesions, and therapeutic maneuvers, all are highly dependent on the quality of the bowel preparation. A significant proportion of patients, in some reports up to one third, are inadequately prepared for the examination, which leads to extended procedure time, incomplete examination, or need for repeat procedure. Aside from efficacy and safety, the most important aspects of colon preparation in pediatrics are ease of administration, palatability, dietary restriction, and minimization of disruption of daily routine. An ideal preparation does not exist and a wide variety of regimens are being used. Several of these have been investigated in pediatric clinical trials. This article reviews the published literature with an emphasis on the most commonly used agents, their mechanism of action, efficacy and ease of use, and safety.

Bowel preparation: current status

Despite emerging evidence from randomized controlled trials and meta-analyses questioning its use, mechanical bowel preparation (MBP) continues to hold an accepted place among surgeons. MBP has been administered to patients for over a century, and though the methods and agents used for intestinal cleansing have evolved over time, many surgeons still embrace MBP as a necessary, essential regimen. The accepted rationale for MBP includes evacuation of stool to allow visualization of the luminal surfaces as well as to reduce the fecal flora, which is believed to translate into lower risk of infectious and anastomotic complications at surgery. The authors describe the history of MBP as it relates to colorectal surgery and review the agents currently used for mechanical bowel preparation. Additionally, they summarize the recent trials, meta-analyses, and other emerging data from the medical literature that suggest MBP offers no benefit as a preoperative measure and question its place in current surgical practice.

Gastrointestinal endoscopy in the elderly: current issues

Even though endoscopy is performed in patients of all ages, currently there is little literature on this topic in elderly patients. As a result of population demographics the use of endoscopy is expected to rise in this section of the population. Elderly patients represent a special group of patients, as they usually have a higher incidence of co-morbid diseases and may be more susceptible to endoscopic interventions. Due to the decreased physiologic reserve and associated diseases, complications in elderly patients can be more severe than in adult or young subjects. Moreover, ethical considerations play a special role in elderly frail patients with a potential poor prognosis. Thus, the endoscopist needs to pay special attention when considering or performing endoscopy in elderly patients. The aim of this article is to review the role of endoscopy in elderly patients, paying special emphasis on indications, special precautions and specific interventions.

Clinical trial: the efficacy and safety of routine bowel cleansing agents for elective colonoscopy in persons with spinal cord injury - a randomized prospective single-blind study

BACKGROUND

As difficulty with evacuation is a common occurrence in individuals with spinal cord injury, preparation prior to colonoscopy may be suboptimal and, perhaps, more hazardous.

AIM

To assess the safety and efficacy of bowel cleansing regimens in persons with spinal cord injury.

METHODS

Randomized, prospective, single blind study comparing polyethylene glycol (PEG), oral sodium phosphosoda (OSPS) and combination of both for colonic preparation prior to colonoscopy in subjects with spinal cord injury.

RESULTS

Thirty six subjects with eGFR > or =60 mL/min/1.73 m(2) were randomized to PEG or OSPS or PEG+OSPS. Regardless of bowel preparation employed, >73% of subjects had unacceptable colonic cleansing. No subject in the OSPS preparation group demonstrated a decrease in eGFR or an increase in serum creatinine concentration from the baseline. OSPS and PEG+OSPS preparations caused a transient change in serum potassium, phosphate and calcium concentrations, but no change in electrolytes was noted in the PEG group.

CONCLUSIONS

Neither OSPS alone, PEG alone nor their combination was sufficient to prepare adequately the bowel for colonoscopy in most patients with spinal cord injury. However, administration of OSPS and/or PEG appears to be safe in the spinal cord injury population, provided adequate hydration is provided.

Bowel preparation before colonoscopy in the era of mass screening for colo-rectal cancer: a practical approach

Colonoscopy constitutes the principal investigation for colo-rectal neoplasms due to its ability to detect and remove most of precancerous lesions; due to the ongoing or planned colon cancer screening programs in many European countries we should expect an enormous increase in colonoscopic demand over the next few years. Diagnostic accuracy and therapeutic safety of colonoscopy strictly depends upon the quality of bowel cleansing which is often perceived as the most unpleasant part of the procedure in individuals undergoing this examination. The ideal preparation for colonoscopy should reliably empty the colon from all faecal material allowing the optimal visualization of the entire colonic mucosa without causing great patient's discomfort nor significant shifts in fluids or electrolytes. Standard PEG solutions and sodium phosphate (NaP) compounds are the most frequently used preparations; both are accepted and relatively well tolerated by the majority of patients undergoing colonoscopy; however, NaP compounds should be avoided in elderly subjects as well as in those with congestive heart failure, renal and hepatic insufficiency or taking diuretics, ACE inhibitors or angiotensin receptor blockers, since they can induce severe electrolyte and/or fluid disturbances. Standard PEG solutions are often taken incompletely due to the low palatability and the high volume of liquids required which induce nausea and vomiting with negative consequences in terms of colon cleansing. Reduced volume and better palatability of PEG solutions, such as those obtained with the newest PEG formulations, as well as improved patient education concerning the importance of bowel cleansing could undoubtedly increase compliance with oral bowel preparations and promote adherence to colo-rectal cancer screening programs.