The effect on colon visualization during colonoscopy of the addition of simethicone to polyethylene glycol-electrolyte solution: a randomized single-blind study

The Effect of Oral Simethicone in a Bowel Preparation in a Colorectal Cancer Screening Colonoscopy Setting: A Randomized Controlled Trial

Introduction

Current guidelines suggest adding oral simethicone to bowel preparation for colonoscopy. However, its effect on key quality indicators for screening colonoscopy remains unclear. The primary aim was to assess the rate of adequate bowel preparation in split-dose high-volume polyethylene glycol (PEG), with or without simethicone.

Methods

This is an endoscopist-blinded, randomized controlled trial, including patients scheduled for colonoscopy after a positive faecal immunochemical test. Patients were randomly assigned to 4 L of PEG split dose (PEG) or 4 L of PEG split dose plus 500 mg oral simethicone (PEG + simethicone). The Boston Bowel Preparation Scale (BBPS) score, the preparation quality regarding bubbles using the Colon Endoscopic Bubble Scale (CEBuS), ADR, CIR, and the intraprocedural use of simethicone were recorded.

Results

We included 191 and 197 patients in the PEG + simethicone group and the PEG group, respectively. When comparing the PEG + simethicone group versus the PEG group, no significant differences in adequate bowel preparation rates (97% vs. 93%; p = 0.11) were found. However, the bubble scale score was significantly lower in the PEG + simethicone group (0 [0] versus 2 [5], p < 0.01), as well as intraprocedural use of simethicone (7% vs. 37%; p < 0.01). ADR (62% vs. 61%; p = 0.86) and CIR (98% vs. 96%, p = 0.14) did not differ between both groups.

Conclusion

Adding oral simethicone to a split-bowel preparation resulted in a lower incidence of bubbles and a lower intraprocedural use of simethicone but no further improvement on the preparation quality or ADR.

Effect of oral simethicone on the quality of colonoscopy: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

In this systematic review and meta-analysis, we aimed to investigate the effect of oral simethicone (SIM), an antifoaming agent, on the quality of colonoscopy in terms of bowel preparation quality, adenoma or polyp detection rate (ADR/PDR) and cecal intubation rate (CIR).

METHODS

All randomized controlled trials (RCTs) on the use of SIM during bowel preparation for colonoscopy published up to 17 March 2021 were identified from the PubMed, EMBASE and Cochrane Library databases. Bowel preparation quality, ADR/PDR/CIR, cecal intubation time (CIT), withdrawal time (WT), patients' tolerability, acceptability and volume of foam and bubbles were compared between the SIM and non-SIM groups.

RESULTS

Thirty-eight RCTs with 10 505 patients were included. Oral SIM significantly increased the rate of total Boston bowel preparation scale (BBPS) score ≥6 (risk ratio [RR]  1.13, P < 0.0001), acceptability (RR  1.15, P = 0.01) and the rate of no or minimal foam and bubbles (RR  1.28, P < 0.00001) and decreased abdominal distension (RR  0.64, P < 0.0001). However, it had no significant impact on overall ADR, overall PDR, CIR, CIT or WT. The rate of total BBPS score ≥6 remained significantly higher in the SIM group when a single-dose laxative regimen or a SIM dosage of ≥320 mg was employed; and ADR, PDR and CIR were significantly increased in the SIM group among colonoscopy clinicians who achieved an ADR <31%, PDR <45% and CIR <96%, respectively.

CONCLUSIONS

Oral SIM can improve bowel preparation quality, especially in patients receiving a SIM dosage of ≥320 mg or a single-dose laxative regimen. SIM may be preferred by junior colonoscopy physicians/trainees with a lower ADR/PDR or CIR.

The Colon Endoscopic Bubble Scale (CEBuS): a two-phase evaluation study

BACKGROUND

To date, no scale has been validated to assess bubbles associated with bowel preparation. This study aimed to develop and assess the reliability of a novel scale - the Colon Endoscopic Bubble Scale (CEBuS).

METHODS

This was a multicenter, prospective, observational study with two online evaluation phases of 45 randomly distributed still colonoscopy images (15 per scale grade). Observers assessed images twice, 2 weeks apart, using CEBuS (CEBuS-0 - no or minimal bubbles, covering < 5 % of the surface; CEBuS-1 - bubbles covering 5 %-50 %; CEBuS-2 - bubbles covering > 50 %) and reporting the clinical action (do nothing; wash with water; wash with simethicone).

RESULTS

CEBuS provided high levels of agreement both in evaluation Phase 1 (4 experts) and Phase 2 (6 experts and 13 non-experts), with almost perfect intraobserver reliability: kappa 0.82 (95 % confidence interval 0.75-0.88) and 0.86 (0.85-0.88); interobserver agreement - intraclass correlation coefficient (ICC) 0.83 (0.73-0.89) and 0.90 (0.86-0.94). Previous endoscopic experience had no influence on agreement among experts vs. non-experts: kappa 0.86 (0.80-0.91) vs. 0.87 (0.84-0.89) and ICC 0.91 (0.87-0.94) vs. 0.90 (0.86-0.94), respectively. Interobserver agreement on clinical action was ICC 0.63 (0.43-0.78) in Phase 1 and 0.77 (0.68-0.84) in Phase 2. Absolute agreement on clinical action per scale grade was 85 % (82-88) for CEBuS-0, 21 % (16-26) for CEBuS-1, and 74 % (70-78) for CEBuS-2.

CONCLUSION

CEBuS proved to be a reliable instrument to standardize the evaluation of colonic bubbles during colonoscopy. Assessment in daily practice is warranted.

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.

Optimal Timing of Simethicone Supplement for Bowel Preparation: A Prospective Randomized Controlled Trial

BACKGROUND AND AIMS

Simethicone (SIM), as an antifoaming agent, has been shown to improve bowel preparation during colonoscopy. However, the optimal timing of SIM addition remained undetermined. We aimed to investigate the optimal timing of SIM addition to polyethylene glycol (PEG) to improve bowel preparation.

METHODS

Eligible patients were randomly assigned to two groups: the SIM evening group (SIM addition to PEG in the evening of the day prior to colonoscopy) and the SIM morning group (SIM addition to PEG in the morning of colonoscopy). The primary outcome was Bubble Scale (BS). The secondary outcomes were Boston Bowel Preparation Scale (BBPS) and adenoma detection rate (ADR).

RESULTS

A total of 419 patients were enrolled in this study. The baseline characteristics of the patients were similar in both groups. No significant differences were observed in terms of BS (8.76 ± 0.90 vs. 8.65 ± 1.16, P = 0.81), ADR (34.1% vs. 30.8%, P = 0.47), Boston Bowel Preparation Scale (BBPS) (8.59 ± 0.94 vs. 8.45 ± 1.00, P = 0.15), and withdrawal time (8.22 ± 2.04 vs. 8.01 ± 2.51, P = 0.094) between the two groups. Moreover, safety and compliance were similar in both groups. However, the SIM evening group was associated with shorter cecal intubation time (3.80 ± 1.81 vs. 4.42 ± 2.03, P < 0.001), higher BS (2.95 ± 0.26 vs. 2.88 ± 0.38, P = 0.04) in the right colon, and diminutive ADR (62.5% vs. 38.6%, P = 0.022) in the right colon, when compared to the SIM evening group.

CONCLUSIONS

The SIM addition to PEG in the evening of the day prior to colonoscopy can shorten cecal intubation time and improve BS scores and diminutive ADR of the right colon compared with the SIM addition to PEG in the morning of colonoscopy in bowel preparation.

The Efficacy of Simethicone With Polyethylene Glycol for Bowel Preparation: A Systematic Review and Meta-Analysis

BACKGROUND

Simethicone (SIM) is a commonly used antifoaming agent in the clinic. However, it has not been clarified whether SIM can improve the quality of intestinal preparation and the detection rates of adenomas (ADR) and polyps (PDR). This systematic review and meta-analysis were carried out to mainly evaluate the effect of SIM in bowel preparation for colonoscopy.

MATERIALS AND METHODS

An electronic and a manual search of the literature for studies was conducted in PubMed, EMBASE, and Web of Science in all published data before February 1, 2020. The primary outcomes were the quality of bowel preparation and the ADR and PDR. All the data were calculated using a pooled estimate of risk ratio with 95% confidence intervals, and a random-effect model was used for the calculation.

RESULTS

Eighteen randomized controlled trials with 7187 patients were included in this meta-analysis. Polyethylene glycol (PEG) with SIM improved colon cleansing (P<0.00001), PDR (P=0.006) and the detection rate of lesions in the right colon (P<0.00001) when compared with PEG alone. There was no difference in the ADR (P=0.68), withdrawal time (P=0.06), cecal intubation rate (P=0.98), and cecal intubation time (P=0.65) between 2 groups. The rate of abdominal bloating rate was higher in the PEG group, but there was no significant difference in vomiting (P=0.65), and abdominal pain (P=0.25).

CONCLUSIONS

SIM improves the quality of bowel cleanliness and PDR but not ADR. Besides, SIM improves the detection rate of lesions in the right colon and decreased abdominal bloating, but do not affect vomiting and abdominal pain or cramping.

Effect of antifoaming agent on benign colorectal tumors in colonoscopy: A meta-analysis

BACKGROUND

Although several trials have shown that the addition of antifoaming agents to polyethylene glycol (PEG) can improve bowel preparation, whether PEG plus antifoaming agents have a beneficial role in the detection of benign tumors during colonoscopy has yet to be confirmed. Our aim was to clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

AIM

To clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched for articles published prior to September 2019. The outcomes included the detection rates of colorectal adenomas and polyps.

RESULT

Twenty studies were eligible. Although there was no difference in the colorectal adenoma detection rate (ADR), a significant effect of simethicone for diminutive adenomas (< 10 mm) was revealed in the group taking simethicone. We also found that simethicone could significantly improve the ADR in the proximal colon but did not affect the colorectal polyp detection rate. Furthermore, the subgroup analyses revealed a beneficial effect of simethicone on the ADR among Asians (P = 0.005) and those with an ADR < 25% (P = 0.003). Moreover, it was a significant finding that the low dose simethicone was as effective as the high dose one with respect to the detection of benign colorectal tumors.

CONCLUSION

In summary, the addition of simethicone to PEG might improve the detection of diminutive adenomas in the right colon by colonoscopy in Asia. Low-dose simethicone was recommended for the detection of benign colorectal tumors. However, large clinical trials are necessary to validate our results and determine the ideal dose of simethicone.

Efficacy of low-dose versus high-dose simethicone with polyethylene glycol for bowel preparation: A prospective randomized controlled trial

BACKGROUND AND AIM

Additional simethicone (SIM) can improve adequate bowel preparation and adenoma detection rate (ADR). However, there is no consensus on the optimal dose of SIM. In this study, we compared the adequate bowel preparation rate with supplementation of split-dose 2 L polyethylene glycol (PEG) with low-dose SIM (200 mg) versus high-dose SIM (1200 mg).

METHODS

This was a prospective, randomized, observer-blinded trial involving consecutive subjects undergoing colonoscopy. The primary outcome was adequate bowel preparation as assessed by Boston Bowel Preparation Scale (BBPS) score.

RESULTS

Four hundred subjects were randomly allocated to low-dose SIM or high-dose SIM group. Baseline characteristics were comparable in the two groups (P > 0.05). No significant between-group differences were observed with respect to total bubble scale (BS) (8.49 ± 1.00 vs 8.39 ± 1.10, P = 0.07), total BBPS score (8.70 ± 0.81 vs 8.29 ± 1.18, P = 0.98), ADR (33.68% vs 31.79%, P = 0.69) or withdrawal time (13 [range, 10-16] min vs 13 [10-15] min, P = 0.96). The intubation time in low-dose SIM group was significantly shorter than that in high-dose SIM group (8 (4-16) min vs 10 [6-17] min, P = 0.04). In addition, BS scores as well as diminutive ADR in right colon were superior in the low-dose SIM group (2.68 ± 0.59 vs 2.52 ± 0.73, P = 0.03 and 54.29% vs 30.30%, P = 0.046, respectively).

CONCLUSION

Addition of low-dose SIM to split-dose 2 L PEG was as effective as addition of high-dose SIM with respect to adequate bowel preparation, ADR and patient tolerance. However, low-dose SIM was superior with respect to intubation time, right colon BS scores, right colon diminutive ADR and cost savings.

Development and Characterization of A New Dimethicone Nanoemulsion and its Application for Electronic Gastroscopy Examination

Purpose

Although the effective and safe medical defoamers, dimethicone (DM) and simethicone (SM) are widely used in electronic gastroscope examination (EGE), their preparations are presented in the form of suspensions or emulsions, these are untransparent or milk-like in appearance and can easily cause misdiagnosis as a result of an unclear field of vision if the doctor does not master the amount of defoamer or operates incorrectly. At the same time, it is also difficult to wash out the camera and pipeline, due to the large oil droplets of preparations. The purpose of this study was to develop a new clear and transparent oil in water (O/W) DM nanoemulsions (DMNs) and observe the effect of application in EGE.

Methods

The oil phase was chosen for its antifoaming activity and viscosity. The emulsifier and co-emulsifier were selected according to the solubility of the oil phase in them. The water titration method was used to make the pseudoternary phase diagrams of nanoemulsions and optimize the prescription composition. DM-in-water nanoemulsion was prepared by the low energy method and evaluated for appearance, antifoaming ability, droplet size, and stability. The effect of DMNs utilized in EGEs was also observed.

Results

The optimal formulation of DMNs contained CRH-40 as an emulsifier, PEG-400 as a co-emulsifier, DM as oil phase with the viscosity of 10 mPa.s, and their proportion was 4.5:4.5:1, respectively. DMNs obtained the average particle size of 67.98 nm with the polydispersity index (PDI) of 0.332, and 57.14% defoaming rate. The result of using an EGE showed that DMNs were superior in comparison to the emulsions with regard to the defoaming effect, visual clarity, and easy cleanup.

Conclusion

DMNs were found to provide excellent visual clarity to its other preparations. The novel DMNs is a promising substitute for DM emulsions or suspensions in EGEs.

The advantage of polyethylene glycol electrolyte solution combined with lactulose in patients with long interval preparation-to-colonoscopy

BACKGROUND/AIMS

The main aim of the present study was to assess the efficacy of polyethylene glycol electrolyte (PEG) solution combined with lactulose in bowel preparation to find a new method for colonoscopy preparation to improve the quality of colonoscopy in patients with long interval preparation-to-colonoscopy (P-C).

MATERIALS AND METHODS

A prospective, randomized, endoscopist-blinded and placebo-controlled study was conducted. Three hundred sixty patients who were scheduled for colonoscopy were enrolled in the study. They were randomly divided into the PEG-lactulose group and the PEG-placebo group with 180 patients per arm. Two of the most common methods for estimating the quality of bowel preparation were the use of the Boston Bowel Preparation Scale and the measurement of the Bubble Scale and adenoma detection rate (ADR) as a secondary outcome of observation.

RESULTS

The PEG-lactulose group had a significant improvement in the quality of bowel preparation compared with the PEG-placebo group including colon cleanliness in interval P-C at 8 and 9 h (p<0.05) and bubble elimination in interval P-C at 5, 6, 7, 8, and 9 h (p<0.05). Compared with the PEG-placebo group, the ADR (23.3% vs. 15.0%, p<0.05) and the size (≤5 mm) of the adenoma (45.2% vs. 18.5%, p<0.05) increased in the PEG-lactulose group, and there were significant differences between the two groups.

CONCLUSION

PEG solution combined with lactulose can improve the quality of colonoscopy in patients with long interval P-C to allow the patients to select more flexible colonoscopy time. It is worth further popularizing in clinical practice.

Effect of simethicone on reducing operative difficulty associated with bowel interference during minilaparotomy for modified Pomeroy salpingectomy: A randomized controlled trial

OBJECTIVE

To examine the effect of simethicone on reducing operative difficulty associated with bowel interference during minilaparotomy for postpartum modified Pomeroy partial salpingectomy.

STUDY DESIGN

We enrolled 20-45-year-old women planning the procedure from March 2018 to February 2019. We randomized participants to chew simethicone 160 mg with water 50 mL 2-8 h before surgery or no treatment. The participants were not blinded; however, surgeons, care providers, and outcome assessors were blinded to the study allocation. We measured surgeon-rated operative difficulty using a 10-cm visual analog scale that represented the difficulty perceived to be resulting from bowel interference. Secondary outcomes included operative time and intraoperative and postoperative complications.

RESULTS

We enrolled 60 women in each group; baseline characteristics and procedural profiles were comparable. Women in the intervention group used simethicone a median of 157 min (interquartile range 127-192) before the procedure. Surgeons rated the procedure difficulty score as 4.8 in the simethicone group and 4.5 in the control group (p = 0.57). Operative time in the two groups were 26 and 24 min, respectively (p = 0.14). We found no difference in intraoperative adverse events including blood loss and mesosalpinx tear, postoperative morbidities, hospital stay, and patient-rated satisfaction scores.

CONCLUSION

Preprocedural simethicone has no demonstrable benefit in reducing operative difficulty caused by bowel interference during minilaparotomy for postpartum tubal sterilization.

IMPLICATIONS

Preprocedural simethicone as given in this study did not result in reduced bowel interference and improved procedure difficulty. Further research examining simethicone in this setting would not be worthwhile as clinically meaningful benefit is unlikely.

Optimal Timing of Simethicone Addition for Bowel Preparation Using Polyethylene Glycol Plus Ascorbic Acid

BACKGROUND

Colonic bubbles obscure the colonic mucosa during colonoscopy following bowel preparation with polyethylene glycol plus ascorbic acid (PEG-Asc). Simethicone is used to enhance visualization during colonoscopy. We aimed to determine the optimal timing of simethicone addition to improve bowel preparation using PEG-Asc.

METHODS

This prospective, randomized study enrolled patients undergoing elective colonoscopy from April 2017 to January 2018. They were randomly assigned to one of the following three groups: PEG-Asc only (control) or simethicone addition in the morning on the day of colonoscopy (PEG-S1) or in the evening of the day prior to colonoscopy (PEG-S2). The primary outcome was the quality of colon cleansing, and the secondary outcomes were the adenoma detection rate (ADR), polyp detection rate (PDR), and diminutive (≤ 5 mm) ADR.

RESULTS

In total, 240 patients were randomly allocated to the three groups; six patients were withdrawn. Of the 234 patients evaluated, 78, 79, and 77 were allocated to the control, PEG-S1, and PEG-S2 groups, respectively. The bubble scores of all colonic segments were lowest in the PEG-S2 group. There was no significant difference in ADR or PDR among the three groups. However, the diminutive ADR was significantly higher in the PEG-S2 group compared to the other two groups (control 5.1% vs. PEG-S1 8.9% vs. PEG-S2 20.8%; P = 0.009).

CONCLUSION

Addition of simethicone to PEG-Asc at the optimal time prevents the formation of air bubbles and so improves the quality of bowel preparation, especially enhancing diminutive ADR.

Simethicone decreases bloating and improves bowel preparation effectiveness: a systematic review and meta-analysis

BACKGROUND

Simethicone is an adjunct frequently used during bowel preparation before colonoscopy and currently there is no consensus on whether it should be recommended in standard bowel preparation. We performed a systematic review and meta-analysis to determine the effect simethicone has on bowel cleanliness, adenoma detection rate (ADR), and tolerability.

METHODS

We searched the literature for studies that compared colon cleansing of patients that received standard bowel preparation alone and in combination with simethicone prior to colonoscopy. The primary outcomes were colon cleanliness, ADR, and tolerability.

RESULTS

Sixteen randomized controlled trials with 5630 patients were included in meta-analysis. Overall, polyethylene glycol (PEG) with simethicone improves colon cleansing compared with PEG alone (odds ratio [OR] 1.48, CI 1.11 to 1.97, P = 0.008). This improvement was seen for single dosing (OR 1.83, CI 1.20 to 2.79, P = 0.005) but not for split dosing (OR 1.32, CI 0.72 to 2.43, P = 0.38). Overall, simethicone had no effect on ADR (OR 1.22, CI 0.81 to 1.83, P = 0.33), but in patients receiving single dosing, simethicone significantly increased ADR (OR 1.96, CI 1.22 to 3.16, P = 0.005). The rates of nausea (OR 0.96, CI 0.75 to 1.24, P = 0.75), vomiting (OR 1.00, CI 0.69 to 1.44, P = 0.99), and abdominal pain (OR 0.69, CI 0.40 to 1.18, P = 0.17) were not significantly different between PEG and PEG + simethicone cohorts. For abdominal bloating, the PEG cohort had greater odds of experiencing bloating than the PEG + simethicone cohort (OR 2.33, CI 1.70 to 3.20, P < 0.00001).

CONCLUSIONS

Simethicone improves colon cleanliness and ADR; however, this improvement is not seen in patients receiving split-dose PEG. Furthermore, simethicone decreases abdominal bloating but has no effect on nausea, vomiting, and abdominal pain. Simethicone may be a useful bowel preparation adjunct in patients unable to receive split-dose PEG.

The role of oral simethicone on the adenoma detection rate and other quality indicators of screening colonoscopy: a randomized, controlled, observer-blinded clinical trial

BACKGROUND AND AIMS

Combining simethicone (SIM) with a colon preparation agent has been shown to improve mucosal visibility during screening colonoscopy, but its effect on the adenoma detection rate (ADR) remains unclear. SIM is commonly used through the endoscope to eliminate bubbles during endoscopy. However, this practice recently has been associated with endoscope-transmitted infections. Our aims were to determine the role of SIM added to a polyethylene glycol preparation on the ADR, procedure times, colon preparation, and intraprocedural use of SIM.

METHODS

This was a randomized, controlled, observer-blinded, clinical trial of patients undergoing screening colonoscopy. Patients with a high risk of colorectal cancer were excluded. Patients were randomly assigned to 2 different preparations: polyethylene glycol plus SIM or polyethylene glycol. Two endoscopists blinded to patient preparation regimens scored its quality by using the Boston Bowel Preparation scale (BBPS) and the bubble scale. Interobserver agreement was calculated. The polyp detection rate, ADR, intraprocedural use of SIM, cecal intubation time, and withdrawal time were recorded. For study purposes, cecal intubation time and withdrawal time were combined to determine the effective procedure time.

RESULTS

No significant difference between the polyethylene glycol plus SIM and polyethylene glycol arms was seen regarding the ADR (33.3% vs 38.8%; P = .881) and effective procedure time (759.3 ± 253.1 seconds vs 800.2 ± 459.6 seconds; P = .373), respectively. Intraprocedural use of SIM as well as the bubble scale score were significantly lower in the polyethylene glycol plus SIM arm (1.6% vs 48.9%; P ≤ .05) and (0.1 vs 2.1; P ≤ .05), respectively. Conversely, no difference was found in the BBPS scores. The interobserver agreement for both scores was strong (bubble scale score kappa = .537; P < .05; BBPS score kappa = .184; P <.05).

CONCLUSION

Adding SIM to a polyethylene glycol preparation did not improve the ADR or effective procedure time. Nevertheless, it resulted in lower bubble scale scores, and more importantly, in less intraprocedural use of SIM. This simple and inexpensive intervention may have the potential to reduce the risk of endoscope-transmitted infections. (Clinical trial registration number: NCT03119168.).

Randomized, double-blinded, placebo-controlled trial evaluating simethicone pretreatment with bowel preparation during colonoscopy

BACKGROUND

The presence of small air bubbles and foam are an impediment to a successful colonoscopy. They impair an endoscopist’s view and diminish the diagnostic accuracy of the study. This has been particularly noted to be of concern with the switch to lower volume polyethylene glycol (PEG) and bisacodyl combination preparation.

AIM

To evaluate the effect of oral simethicone addition to bowel preparation on intraluminal bubbles reduction during colonoscopy.

METHODS

Described is a prospective, randomized, multi-center, double-blinded, placebo-controlled study to evaluate the use of premixed simethicone formulation with split-regimen, low-volume PEG-bisacodyl combination bowel preparation for 168 outpatients undergoing screening, surveillance, and diagnostic colonoscopies. Primary outcome includes evaluation of bubbles during colonoscopy graded using the Intraluminal Bubbles Scale. Secondary outcomes include evaluation of the Boston Bowel Preparation Scale (BBPS), total number of polyps, polyp size differentiation, polyp laterality, adenoma detection, mass detection, cecal insertion time, withdrawal time, and patient-reported adverse events.

RESULTS

Higher Intraluminal Bubbles grades III and IV (less than 75% of the mucosa cleared of bubbles/foam requiring intervention with simethicone infused wash) were detected in the placebo group [Simethicone n = 4/84 vs Placebo n = 20/84 (P = 0.007)]. BBPS total score was 7.42 [standard deviation (SD) = ± 1.51] in the simethicone group and 7.28 (SD = ± 1.44) in the placebo group (P = 0.542) from a total of 9. Significantly higher number of adenomas were detected in the simethicone group (P = 0.001).

CONCLUSION

The addition of simethicone to bowel preparation is well advised for its anti-foaming properties. The results of this study suggest that addition of oral simethicone can improve bowel wall visibility.

Widespread clinical use of simethicone, insoluble lubricants, and tissue glue during endoscopy: A call to action for infection preventionists

BACKGROUND

Current methods for reprocessing flexible endoscopes do not consistently eliminate organic soil. The off-label use of simethicone as a defoaming agent may contribute to reprocessing failures, and endoscope manufacturers have cautioned against its use.

METHODS

We sought evidence of simethicone use by interviewing hospital personnel, conducting audits, inspecting endoscopes, and conducting tests.

RESULTS

Researchers examined 69 fully reprocessed endoscopes in 4 hospitals. Microbial cultures were positive for ≥50% of endoscopes. Researchers observed cloudy, shimmery fluid resembling simethicone inside channels and under a duodenoscope elevator mechanism. Crystallized white fragments were observed protruding from a gastroscope water jet outlet. Oily, sticky residue was found on endoscopes, and a 3-dimensional mass was found inside an endoscopic ultrasound endoscope. Hospital personnel reported the use of simethicone, cooking oil and silicone sprays, and tissue glue during endoscopy.

DISCUSSION

The off-label use of defoaming agents, lubricants, and tissue glue is common and many endoscopists consider these products essential. Our findings suggest these substances are not removed during reprocessing and may impact reprocessing effectiveness.

CONCLUSIONS

Infection preventionists should determine whether these products are used in their institutions and evaluate methods for removing them. New policies may be needed to support procedural success and effective endoscope reprocessing.

The benefit of adding oral simethicone in bowel preparation regimen for the detection of colon adenoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Simethicone is an anti-foaming agent commonly used during colonoscopy. Although several randomized trials have shown that oral simethicone in the bowel preparation regimen may improve bowel cleanness, whether it improves adenoma detection rate (ADR) or polyp detection rate remains undetermined. The aim of this study was to determine if oral simethicone in bowel preparation regimen before colonoscopy improves the ADR.

METHODS

A comprehensive literature review was conducted using PubMed, SDOL, Cochrane Library, and ProQuest databases through December 2017. Randomized controlled trials that compared bowel preparation regimens with simethicone versus those without it were included. Effect estimates from each study were extracted and underwent meta-analysis using appropriate models. The primary outcomes were ADR and polyp detection rate, and secondary outcomes included bowel preparation, bubble score, and withdrawal time.

RESULTS

Twelve published randomized controlled studies with 6003 participants were included for meta-analysis. There was no difference in the overall ADR (pooled risk ratio = 1.06, 95% confidence interval = 0.91-1.24) and right-side ADR (risk ratio = 1.50, 95% confidence interval = 0.82-2.75) between the groups with or without simethicone. However, the addition of simethicone improved adenoma detected per patient (2.20 ± 1.36 vs 1.63 ± 0.89) according to one of the included studies. Meta-regression revealed that the baseline ADR < 25% of the included studies was associated with significant benefit of oral simethicone; the number needed to treat was 15.

CONCLUSIONS

The adjunction of oral simethicone significantly improved bowel preparation quality and might benefit adenoma detection in specific settings with low baseline ADR.

Higher dose of simethicone decreases colonic bubbles and increases prep tolerance and quality of bowel prep: Meta-analysis of randomized controlled trials

BACKGROUND

Antifoaming agents, such as simethicone, may facilitate mucosal inspection during colonoscopy. However, conflicting results have been reported with regard to the impact of simethicone on quality of bowel preparation and adenoma detection rate (ADR).

AIM

To perform a meta-analysis of trials that have compared simethicone vs placebo during colonoscopy.

METHODS

A reproducible literature search of multiple medical databases yielded eleven studies (n = 2605) for inclusion. Studies were compared for quality of bowel preparation, bubbles quality, ADR, and tolerability. Two reviewers independently scored the identified studies for methodology and abstracted pertinent data. Pooling was conducted by both fixed-effects and random-effects models. Relative risk (RR) estimates with a 95% confidence interval (CI) were calculated. Heterogeneity was assessed by I-squared index (I²) statistics.

RESULTS

Patients’ demographic characteristics were comparable in all studies. Of the 2605 patients, 1300 were in the simethicone group, whereas 1305 were in the placebo group. Inadequate bowel preparation was much lower in the simethicone group than in the placebo group [13% vs 24.6%; RR = 0.51 (0.31-0.82); P < 0.0001]. The placebo group was more likely to have significant colonic bubbles than was the simethicone group [35% vs 8%; RR = 1.49 (1.25-1.76); P = 0.0001]. Use of simethicone resulted in a slight, statistically significant increase in ADR compared with the placebo group [26.6% vs 21.6%, RR = 1.07 (1.01-1.13); P = 0.02]. Higher doses of simethicone (> 478 mg) were more likely to result in significant reduction of inadequate bowel preparation, colonic bubbles, and to improve ADR.

CONCLUSION

Adding simethicone improved the quality of bowel preparation, visualization, tolerability, and, eventually, ADR.

Water Exchange Produces Significantly Higher Adenoma Detection Rate Than Water Immersion: Pooled Data From 2 Multisite Randomized Controlled Trials

GOALS

To test the hypothesis that water exchange (WE) significantly increases adenoma detection rates (ADR) compared with water immersion (WI).

BACKGROUND

Low ADR was linked to increased risk for interval colorectal cancers and related deaths. Two recent randomized controlled trials of head-to-head comparison of WE, WI, and traditional air insufflation (AI) each showed that WE achieved significantly higher ADR than AI, but not WI. The data were pooled from these 2 studies to test the above hypothesis.

STUDY

Two trials (5 sites, 14 colonoscopists) that randomized 1875 patients 1:1:1 to AI, WI, or WE were pooled and analyzed with ADR as the primary outcome.

RESULTS

The ADR of AI (39.5%) and WI (42.4%) were comparable, significantly lower than that of WE (49.6%) (vs. AI P=0.001; vs. WI P=0.033). WE insertion time was 3 minutes longer than that of AI (P<0.001). WE showed significantly higher detection rate (vs. AI) of the >10 mm advanced adenomas. Right colon combined advanced and sessile serrated ADR of AI (3.4%) and WI (5%) were comparable and were significantly lower than that of WE (8.5%) (vs. AI P<0.001; vs. WI P=0.039).

CONCLUSIONS

Compared with AI and WI, the superior ADR of WE offsets the drawback of a significantly longer insertion time. For quality improvement focused on increasing adenoma detection, WE is preferred over WI. The hypothesis that WE could lower the risk of interval colorectal cancers and related deaths should be tested.

Effect of supplemental simethicone for bowel preparation on adenoma detection during colonoscopy: A meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Although several randomized controlled trials (RCTs) have reported that supplemental simethicone (SIM) can improve bowel preparation based on polyethylene glycol, there is no consensus as to whether SIM can ultimately increase the adenoma detection rate (ADR) during colonoscopy. A meta-analysis was performed to assess the effect of SIM on ADR during colonoscopy.

METHODS

Databases including PubMed, EMBASE, and the Cochrane Library were searched to find relevant RCTs. RCTs evaluating the effect of pre-procedure SIM on the ADR during colonoscopy were finally included, and fixed effect models were applied.

RESULTS

Six trials involving 1855 patients were finally included. The present meta-analysis suggested that the ADR during colonoscopy was significantly increased by supplemental SIM (27.9% vs 23.3%, P = 0.02), with a relative risk of 1.20 (95% confidence interval 1.03-1.39). Subgroup analysis suggested that supplemental SIM may be more useful to improve ADR during colonoscopy in endoscopic centers with low baseline ADR.

CONCLUSIONS

Supplemental SIM for bowel preparation based on polyethylene glycol is useful to improve the ADR during colonoscopy.

Simethicone is retained in endoscopes despite reprocessing: impact of its use on working channel fluid retention and adenosine triphosphate bioluminescence values (with video)

BACKGROUND AND AIMS

Studies from our group and others demonstrate residual fluid in 42% to 95% of endoscope working channels despite high-level disinfection and drying. Additionally, persistent simethicone has been reported in endoscope channels despite reprocessing.

METHODS

Endoscopy was performed by using water or varied simethicone concentrations (0.5%, 1%, 3%) for flushing. After high-level disinfection/drying, we inspected endoscope working channels for retained fluid by using the SteriCam borescope. Working channel rinsates were evaluated for adenosine triphosphate (ATP) bioluminescence. Fourier transform infrared spectroscopy was performed on fluid droplets gathered from a colonoscope in which low-concentration simethicone was used.

RESULTS

Use of medium/high concentrations of simethicone resulted in a higher mean number of fluid droplets (13.5/17.3 droplets, respectively) and ATP bioluminescence values (20.6/23 relative light units [RLUs], respectively) compared with that of procedures using only water (6.3 droplets/10.9 RLUs; P < .001). Two automated endoscope reprocessing cycles resulted in return of a fluid droplet and ATP bioluminescence values to ranges similar to that of procedures that used only water (P = .56). Low-concentration simethicone did not increase the mean residual fluid or ATP bioluminescence values compared with procedures that used only water (5.8 droplets/15.6 RLUs). Fourier transform infrared analysis revealed simethicone in the endoscope working channel after use of low-concentration simethicone.

CONCLUSIONS

Use of medium/high concentrations of simethicone is associated with retention of increased fluid droplets and higher ATP bioluminescence values in endoscope working channels, compared with endoscopes in which water or low concentration simethicone was used. However, simethicone is detectable in endoscopes despite reprocessing, even when it is utilized in low concentrations. Our data suggest that when simethicone is used, it should be used in the lowest concentration possible. Facilities may consider 2 automated endoscope reprocessor cycles for reprocessing of endoscopes when simethicone has been used.

Canadian Association of Gastroenterology Position Statement on the Impact of Simethicone on Endoscope Reprocessing

A recent study by Ofstead et al. published in the American Journal of Infection Control described the presence of residual simethicone and non-pathogenic bacterial colonization in endoscopes despite adherence to reprocessing procedures(1). These findings received significant media attention, in part because they were released following a warning issued by the Food and Drug Administration and the Centre for Disease Control regarding the potential transmission of multi-drug resistant bacteria associated with the use of duodenoscopes(2, 3). In light of the findings described by Ofstead et al., the Canadian Association of Gastroenterology (CAG) would like to update its members on what is currently known.

Prospective multicenter randomized controlled trial comparing adenoma detection rate in colonoscopy using water exchange, water immersion, and air insufflation

BACKGROUND AND AIMS

Adenoma detection rate (ADR), defined as the proportion of patients with at least one adenoma of any size, is a quality indicator. We tested the hypothesis that water exchange (WE) improves ADR but water immersion (WI) has no adverse effect on ADR compared with air insufflation (AI).

METHODS

A prospective study was conducted at the Dalin Tzu Chi Hospital in southern Taiwan and the Hualien Tzu Chi Hospital in eastern Taiwan on patients randomly assigned to WE, WI, or AI with stratification by the 3 study colonoscopists. The primary outcome was ADR.

RESULTS

From July 2013 to December 2015, 651 patients were recruited and randomized into 3 groups with a 1:1:1 ratio (217 patients per group). Overall, ADR met quality standards: WE 49.8% (95% CI, 43.2%-56.4%), AI 37.8% (95% CI, 31.6%-44.4%), and WI 40.6% (95% CI, 34.2%-47.2%). Compared with AI, WE significantly increased ADR (P = .016). There was no difference between WI and WE. ADRs of WI and AI were comparable. Compared with AI, WE confirmed a longer insertion time, higher cleanliness score, but similar adenoma per positive colonoscopy (APPC) and withdrawal time with polypectomy. Subgroup analysis found WE significantly increased ADR in propofol-sedated patients. Multivariate generalized linear mixed model analysis revealed that age ≥50 years, WE (vs AI), colonoscopy indication, no previous history of colonoscopy, and withdrawal time >8 minutes were significant predictors of increased ADR.

CONCLUSIONS

Confirmation of prior reports showing WE, but not WI, increased ADR further strengthened the validity of our observations. WE significantly increased ADR in propofol-sedated patients. The outcome differences justify assessment of the role of WE in colorectal cancer prevention. Similar APPC and withdrawal times suggest that adequate inspection was performed on colonoscope withdrawal in each of the study arms. (Clinical trial registration number: NCT01894191.).

Simethicone residue remains inside gastrointestinal endoscopes despite reprocessing

BACKGROUND

During a study designed to assess endoscope reprocessing effectiveness, a borescope was used to examine lumens and ports. Cloudy, white, viscous fluid was observed inside fully reprocessed gastroscopes and colonoscopes. This fluid resembled simethicone, which is commonly administered to reduce foam and bubbles that impede visualization during gastrointestinal endoscopy. This article describes methods used to determine whether the observed fluid contained simethicone.

METHODS

Photographs of residual fluid were taken using a borescope. Sterile cotton-tipped swabs were used to collect samples of fluid observed in 3 endoscope ports. Samples were evaluated using Fourier transform infrared spectroscopy (FTIR)-attenuated total reflection analysis.

RESULTS

Residual fluid was observed inside 19 of 20 endoscopes. Fluid photographed in 8 endoscopes resembled simethicone solutions. FTIR analysis confirmed the presence of simethicone in 2 endoscopes.

CONCLUSIONS

Fluid containing simethicone remained inside endoscopes despite reprocessing. Simethicone is an inert, hydrophobic substance that may reduce reprocessing effectiveness. Simethicone solutions commonly contain sugars and thickeners, which may contribute to microbial growth and biofilm development. Studies are needed to assess the prevalence of residual moisture and simethicone in endoscopes and determine the impact on reprocessing effectiveness. We recommend minimizing the use of simethicone pending further research into its safety.

Clinical application of methods for improving quality of colonoscopy procedure

AIM: To assess the effect of three controllable clinical factors (bowel preparation, observation methods of doctors and comfort degree of patients) on the quality of colonoscopy to improve the quality of colonoscopy.

METHODS: Nine hundred outpatients who underwent conventional colonoscopy were randomly selected and divided into different groups, based on bowel preparation, observation methods of doctors, and use of pinaverium bromide tablets or not. An experienced colonoscopist recorded the hygienic level of the bowel on a Boston Bowel Preparation Scale, assessed the degree of bubbles, assessed the degree of pain, and recorded the polyp detection rate and small polyp detection rate.

RESULTS: There was no significant difference in bowel preparation among different groups (P > 0.05). The bubble volume (especially in the right-side colon) in patients treated with espumisan was less than that in patients treated with polyethylene glycol electrolyte powder alone (P < 0.05). The degree of pain in patients treated with pinaverium bromide was less than that in patients treated with scopolamine (P < 0.05). The polyp detection rate and the small polyp detection rate were significantly higher in patients who were observed in the insertion and withdrawal group than in the withdrawal alone group (P < 0.05).

CONCLUSION: The bowel can be effectively cleaned with polyethylene glycol electrolyte powder, and the bubble volume can be effectively reduced after taking espumisan. The pain degree of patients taking pinaverium bromide is less than that of patients without taking. The polyp detection rate and small polyp detection rate are higher in the insertion and withdrawal group than the withdrawal alone group. These results indicate that the quality of colonoscopy could be effectively improved by all the above ways.

2-Litre polyethylene glycol-citrate-simethicone plus bisacodyl versus 4-litre polyethylene glycol as preparation for colonoscopy in chronic constipation

BACKGROUND

Chronic constipation is a risk factor of inadequate bowel preparation for colonoscopy; however, no large clinical trials have been performed in this subgroup of patients.

AIMS

To compare bowel cleansing efficacy, tolerability and acceptability of 2-L polyethylene-glycol-citrate-simethicone (PEG-CS) plus 2-day bisacodyl (reinforced regimen) vs. 4-L PEG in patients with chronic constipation undergoing colonoscopy.

METHODS

Randomized, observer-blind, parallel group study. Adult outpatients undergoing colonoscopy were randomly allocated to 2-L PEG-CS/bisacodyl or 4-L PEG, taken as split regimens before colonoscopy. Quality of bowel preparation was assessed by the Ottawa Bowel Cleansing Scale (OBCS). The amount of foam/bubble interfering with colonic visualization was also measured.

RESULTS

400 patients were enrolled. There was no significant difference in successful cleansing (OBCS score ≤6): 80.2% in the 2-L PEG-CS/bisacodyl vs. 81.4% in the 4-L PEG group. Significantly more patients taking 2L PEG-CS/bisacodyl showed no or minimal foam/bubbles in all colonic segments (80% vs. 63%; p<0.001). 2-L PEG-CS/bisacodyl was significantly more acceptable for ease of administration (p<0.001), willingness to repeat (p<0.001) and showed better compliance (p=0.002).

CONCLUSION

Split 2-L PEG-CS plus bisacodyl was not superior to split 4-L PEG for colonoscopy bowel cleansing in patients with chronic constipation; however, it performed better than the standard regimen in terms of colonic mucosa visualization, patient acceptance and compliance.

Simethicone to prevent colonic bubbles during CT colonography performed with polyethylene glycol lavage and iohexol tagging: a randomized clinical trial

OBJECTIVE

The purpose of this study was to determine whether the occurrence of numerous colonic bubbles during CT colonography (CTC) performed with polyethylene glycol cleansing and oral iohexol fecal/fluid tagging could be prevented by use of simethicone.

SUBJECTS AND METHODS

Adults with suspected colonic neoplasia who had been randomly assigned to control and simethicone intervention groups underwent CTC after cleansing with 4 L of polyethylene glycol, tagging with 50 mL of 350 mg I/mL oral iohexol, and without (control) or with (intervention) oral administration of 200 mg of simethicone. Colonic segments in the control and intervention groups were evaluated for amount of colonic bubbles during CTC. A 6-point grading system was used in which 0 indicated no bubbles and 5 indicated that more than three fourths of the air-distended mucosa was covered with bubbles. The primary endpoint was a per-patient colonic bubble grade, derived as an average of the segmental grades.

RESULTS

Eighty adults with suspected colonic neoplasia were randomly assigned to the control (40 patients) and simethicone intervention (40 patients) groups. A total of 659 colonic segments in the control group and 689 segments in the intervention group were evaluated for amount of colonic bubbles during CTC. The per-patient colonic bubble score was significantly lower in the simethicone intervention group than in the control group. The mean score was 0.0±0.1 (SD) versus 1.2±0.8 (p<0.001; 95% CI for the mean difference, -1.4 to -1.0). In the intervention group, 673 (97.7%) segments were grade 0, and 16 (2.3%) were grade 1. In contrast, in the control group, 226 (34.3%) segments were grade 0; 173 (26.3%), grade 1; 175 (26.6%), grade 2; 45 (6.8%), grade 3; 23 (3.5%), grade 4; and 17 (2.6%), grade 5.

CONCLUSION

The colonic bubbles associated with fecal/fluid tagging with iohexol can be successfully prevented by adding simethicone to the colonic preparation.

Benefit of a 360-degree horizontal turn following premedication with simethicone on image quality during gastroendoscopy: a randomized controlled trial

OBJECTIVES

To investigate whether a 360-degree horizontal turn after oral premedication with simethicone improves the mucosal visibility during gastroendoscopic examination, and to determine the proper time to turn over the patient.

METHODS

This study involved 993 patients scheduled for gastroendoscopy. Just before gastroendoscopy, after oral premedication with simethicone, patients were randomly assigned to three groups: in Group A, patients waited for 20 min before gastroendoscopy; in Group B, patients were separately waited for 5/10/15/20 min and were then turned 360 degrees just before gastroendoscopy; in Group C, patients were immediately turned 360 degrees and then separately waited for 5/10/15/20 min before examination. The sum of the gastric mucosal visibility scores (MVS) was calculated after the examination. The MVS and proportion of images with higher visibility scores for the mucosal surface. Lower scores indicate better visibility of the mucosal surface.

RESULTS

In Groups B and Groups C, when waiting time more than 10 min had lower mean total MVS than Group A. The MVS of four subgroups of Group B were not different from those of Group C.

CONCLUSION

Oral premedication with simethicone and immediately make a body posture change (turning over 360 degrees) then waiting for 10min can increase the image quality during gastroendoscopy and effectively decrease the premedication time.

Iohexol versus diatrizoate for fecal/fluid tagging during CT colonography performed with cathartic preparation: comparison of examination quality

OBJECTIVE

We aimed to compare iohexol vs. diatrizoate as fecal/fluid tagging agents for computed tomography colonography (CTC) regarding examination quality.

METHODS

Forty prospective patients (M:F = 23:17; 63 ± 11.6 years) received CTC using 50 mL (350 mgI/mL) oral iohexol for tagging. Forty other indication-matched, age-matched, and sex-matched patients who underwent CTC using 100 mL diatrizoate for tagging and otherwise the same technique, were retrospectively identified. Two groups were compared regarding overall examination quality, per-patient and per-segment scores of colonic bubbles (0 [no bubbles] to 5 [the largest amount]), and the volume, attenuation, and homogeneity (untagged, layered, and homogeneous) of the residual colonic fluid.

RESULTS

The iohexol group demonstrated a greater amount of colonic bubbles than the diatrizoate group: mean per-patient scores ± SD of 1.2 ± 0.8 vs. 0.7 ± 0.6, respectively (p = 0.003); and rates of segments showing ≥ grade 3 bubbles of 12.9 % (85/659) vs. 1.6 % (11/695), respectively (p = 0.001). Residual colonic fluid amount standardized to the colonic volume did not significantly differ: 7.2 % ± 4.2 vs. 7.8 % ± 3.7, respectively (p = 0.544). Tagged fluid attenuation was mostly comparable between groups and the fluid was homogeneously tagged in 98.7 % (224/227) vs. 99.5 % (218/219) segments, respectively (p = 0.344). Iohexol caused more colonic bubbles when used during cathartic CTC. Otherwise, examination quality was similarly adequate with both iohexol and diatrizoate.

KEY POINTS

• When used for tagging, iohexol caused significantly more colonic bubbles than diatrizoate. • The residual colonic fluid amount did not significantly differ between iohexol and diatrizoate. • The quality of fluid tagging was similarly adequate in both iohexol and diatrizoate.

Adjuncts to colonic cleansing before colonoscopy

Pre-procedural cleansing of the bowel can maximize the effectiveness and efficiency of colonoscopy. Yet, efficacy of the current gold standard colonic preparation method - high-volume oral administration of purgative agents 12-24 h prior to the procedure - is limited by several factors, such as patient compliance (due to poor palatability and inconvenience of the dosing regimen) and risks of complications (due to drug interactions or intolerance). Attempts to resolve these limitations have included providing adjunctive agents and methods to promote the colonic cleansing ability of the principal purgative agent, with the aim of lessening unpleasant side effects (such as bloating) and reducing the large ingested volume requirement. Several promising adjunctive agents are bisacodyl, magnesium citrate, senna, simethicone, metoclopramide, and prokinetics, and each are being investigated for their potential. This review provides an up to date summary of the reported investigations into the potencies and weaknesses of the key adjuncts currently being applied in clinic as supplements to the traditional bowel preparation agents. While the comparative analysis of these adjuncts showed that no single agent or method has yet achieved the goal of completely overcoming the limitations of the current gold standard preparation method, they at least provide endoscopists with an array of alternatives to help improve the suboptimal efficacy of the main cleansing solutions when used alone. To aid in this clinical endeavor, a subjective grade was assigned to each adjunct to indicate its practical value. In addition, the systematic review of the currently available agents and methods provides insight into the features of each that may be overcome or exploited to create novel drugs and strategies that may become adopted as effective bowel cleansing adjuncts or alternatives.