Bowel preparation, the first step for a good quality colonoscopy

Strategies to improve screening colonoscopy quality for the prevention of colorectal cancer

The incidence and mortality of colorectal cancer (CRC) have decreased through regular screening colonoscopy, surveillance, and endoscopic treatment. However, CRC can still be diagnosed after negative colonoscopy. Such CRC is called interval CRC and accounts for 1.8-9.0% of all CRC cases. Most cases of interval CRC originate from missed lesions and incompletely resected lesions. Interval CRC can be minimized by improving the quality of colonoscopy. This has led to a growing interest in and demand for high-quality colonoscopy. It is important to reduce the risk of CRC and its associated mortality by improving the quality of colonoscopy. In this review article, we provide an overview of colonoscopy quality indicators, including bowel preparation adequacy, the cecal intubation rate, the adenoma detection rate, the colonoscopy withdrawal time, appropriate polypectomy, and complication of the procedure. Because colonoscopy is a highly endoscopist-dependent procedure, colonoscopists should be well-acquainted with quality indicators and strive to apply them in daily clinical practice for the prevention of CRC.

Small Bowel Capsule Endoscopy within 6 Hours Following Bowel Preparation with Polyethylene Glycol Shows Improved Small Bowel Visibility

Although bowel preparation influences small bowel visibility for small bowel capsule endoscopy (SBCE), the optimal timing for bowel preparation has not been established yet. Thus, the aim of the study was to evaluate the optimal timing of polyethylene glycol (PEG) for small bowel preparation before SBCE. This multicenter prospective observational study was conducted on patients who underwent SBCE following bowel preparation with polyethylene glycol (PEG). Patients were categorized into three groups according to the time used for completing PEG ingestion: group A, within 6 h; group B, 6-12 h; and group C, over 12 h. The percentage of unclean segment in small bowel (unclean image duration / small bowel transit time × 100) and small bowel visibility quality (SBVQ) were evaluated according to the time interval between the last ingestion of PEG and swallowing of small bowel capsule endoscope. A total of 90 patients were enrolled and categorized into group A (n = 40), group B (n = 27), and group C (n = 23). The percentage of unclean segment in the entire small bowel increased gradually from group A to C (6.6 ± 7.6% in group A, 11.3 ± 11.8% in group B, and 16.2 ± 10.7% in group C, p = 0.001), especially in the distal small bowel (11.4 ± 13.6% in group A, 20.7 ± 18.7% in group B, and 29.5 ± 16.4% in group C, p < 0.001). The proportion of patients with adequate SBVQ in group A was significantly (p < 0.001) higher (30/40, 75.0%) than that in group B (17/27, 63.0%) or group C (5/23, 21.7%). In multivariate analysis, group A was associated with an increased likelihood of adequate SBVQ compared with group C (odds ratio [OR]: 13.05; 95% confidence interval [CI]: 3.53-48.30, p < 0.001). Completing PEG ingestion within 6 h prior to SBCE could enhance small bowel visibility.

Efficacy of elobixibat as bowel preparation agent for colonoscopy: Prospective, randomized, multi-center study

BACKGROUND AND AIM

Elobixibat is a novel ileal bile acid transporter inhibitor. This study aimed to compare the efficacy, tolerability, and safety of the combination of elobixibat and 1 L of polyethylene glycol formulation containing ascorbic acid (PEG-Asc) solution versus the combination of sodium picosulfate and 1-L PEG-Asc solution as bowel preparation for colonoscopy.

METHODS

This multi-center, randomized, observer-blinded, non-inferiority study recruited 210 outpatients who were assigned to either the elobixibat plus 1-L PEG-Asc group (group A) or the sodium picosulfate plus 1-L PEG-Asc group (group B). The quality of the bowel cleansing level was assessed by the Boston Bowel Preparation Scale (BBPS) and compared the bowel cleansing level between the groups. Data regarding bowel preparation time, patients' tolerability, and adverse events were also analyzed.

RESULTS

Data for 196 patients (99 in group A and 97 in group B) were analyzed finally. BBPS was comparable between group A and B (8.3 ± 0.9 vs. 8.3 ± 0.7; P = 0.88). Consequently, the adequate bowel preparation rate in groups A and B was 95.0% and 99.0%, respectively (-4.0%, 95% CI -9.3 to 1.5). Bowel preparation time in group A was similar to that in group B (348.2 ± 79.8 min vs. 330.8 ± 82.5 min; P = 0.13), whereas, sleep disturbance was significantly less frequent in group A than in group B (10.2% vs. 22.7%; P = 0.02).

CONCLUSIONS

The combination of elobixibat and 1-L PEG-Asc can be considered an alternative bowel preparation for colonoscopy considering the equivalent bowel cleansing effect and less frequent sleep disturbance. The Japan Registry of Clinical Trials (jRCTs41180026).

Postgastrectomy gastric cancer patients are at high risk for colorectal neoplasia: a case control study

Background/Aims

Several studies have shown that colorectal neoplasms (CRN) including colorectal cancer (CRC) may be prevalent in patients with gastric cancer. However, in most of these studies, colonoscopy to investigate the prevalence of CRN was performed prior to surgery. We aimed to investigate whether CRN was more prevalent in postgastrectomy gastric cancer patients than in healthy individuals.

Methods

We reviewed the medical records of those patients within a cohort of gastric cancer patients with gastrectomy who underwent colonoscopy between 2016 and 2017. Controls age- and sex-matched with gastric cancer patients at a 2:1 ratio were identified among those who underwent colonoscopy at a health-promotion center. The frequencies of CRN, advanced CRN (ACRN), and CRC among patients with gastrectomy were compared with those in the control subjects. A total of 744 individuals (gastric cancer, 248; control, 496) were included.

Results

The rates of CRN and ACRN in the gastric cancer group were higher than those in the healthy individuals (CRN, 47.6% vs. 34.7%, P<0.001; ACRN, 16.9% vs. 10.9%, P=0.020). The rate of CRC was comparable between the 2 groups (2.0% vs. 0.6%, P=0.125). Multivariate analysis identified previous gastrectomy for gastric cancer and male sex as significant risk factors for (A)CRN.

Conclusions

CRN and ACRN were more prevalent in patients who underwent surgery for gastric cancer than in the control group. Regular surveillance colonoscopy at appropriate intervals is indicated after gastrectomy.

Comparison of bowel-cleansing efficacy of split-dose and same-day dose bowel preparation for afternoon colonoscopy in patients with gastrectomy: a prospective randomized study

BACKGROUND

A split dose (SPD) of purgative is the recommended bowel-preparation method for colonoscopy, although for colonoscopy scheduled for the afternoon, a same-day dose (SDD) of purgative is recommended. However, it has not been determined whether SPD or SDD is better in patients with gastrectomy who are at high risk of suboptimal bowel cleansing. We compared the bowel-cleansing efficacy of SPD and SDD regimens in patients with gastrectomy who underwent colonoscopy in the afternoon.

METHODS

This was a prospective, randomized, assessor-blinded study. For the SDD group, polyethylene glycol (PEG) was ingested on the day of colonoscopy starting at 7 AM. In the SPD group, 2 L PEG was ingested at 9 PM the day before colonoscopy, and the remaining 2 L from 10 AM on the day of colonoscopy. Colonoscopy was performed from 1:30 PM. Before colonoscopy, the participants completed questionnaires asking about bowel-movement kinetics, adverse events, tolerability, overall satisfaction, and willingness to reuse the protocol. The bowel-cleansing efficacy was assessed using the Boston Bowel Preparation Scale.

RESULTS

A total of 193 subjects were included (SDD, 95; SPD, 98). The rate of successful bowel cleansing was comparable between the two groups (SDD, 92.6% vs. SPD, 95.9%; P = 0.37). The incidence of adverse events (nausea, vomiting, bloating, abdominal pain, and dizziness/headache) was also comparable between the two groups. However, sleep disturbance was higher in the SPD group (SDD, 10.5% vs. SPD, 25.5%; P = 0.01). Tolerability did not differ between the SDD and SPD groups (satisfaction, P = 0.11; willingness to reuse, P = 0.29).

CONCLUSIONS

The bowel-cleansing efficacy, safety profile, and patient tolerability of SDD and SPD were comparable. Both SDD and SPD regimens are feasible bowel-preparation methods for patients with gastrectomy who undergo colonoscopy in the afternoon.

TRIAL REGISTRATION

Clinical trial registration number: KCT0002699.

Comparison of Bowel Cleansing Efficacy, Safety, Bowel Movement Kinetics, and Patient Tolerability of Same-Day and Split-Dose Bowel Preparation Using 4 L of Polyethylene Glycol: A Prospective Randomized Study

BACKGROUND

Split-dose bowel preparation is recommended for morning colonoscopy, although a same-day dose regimen is an alternative for afternoon colonoscopy. Same-day preparation for morning colonoscopy has rarely been evaluated.

OBJECTIVE

We compared the bowel cleansing efficacy, bowel movement kinetics, safety profile, and patient tolerability of split-dose and same-day preparation using 4-L polyethylene glycol.

DESIGN

This was a prospective, randomized, assessor-blinded study.

SETTINGS

This study was performed at a tertiary center in Korea.

PATIENTS

Study subjects were randomly assigned to the same-day or split-dose groups. For the same-day dose group, 4 L of polyethylene glycol were ingested on the day of colonoscopy starting at 5:00 AM for morning colonoscopy or 7:00 AM for afternoon colonoscopy. In the split-dose group, 2 L of polyethylene glycol were ingested at 9:00 PM the day before colonoscopy, and the remaining 2 L from 7:00 AM for morning colonoscopy or from 10:00 AM for afternoon colonoscopy. Colonoscopy was performed from 10:00 AM.

MAIN OUTCOME MEASURES

The efficacy of bowel cleansing was evaluated using the Boston bowel preparation scale. The participants completed questionnaires asking about adverse events, bowel movement kinetics, and tolerability of the preparation before colonoscopy.

RESULTS

A total of 339 subjects were included (same-day dose = 172; split dose = 167). One subject in each group did not undergo colonoscopy. The rate of successful cleansing did not differ between the groups (same-day dose = 98.8% vs split dose = 98.2%; p = 0.681). There were no instances of hemodynamic instability or aspiration in either group. Tolerability, including overall satisfaction and willingness to reuse, were comparable between the groups.

LIMITATIONS

This was a single-center study.

CONCLUSIONS

The bowel cleansing efficacy, safety profile, and tolerability of same-day dosing with polyethylene glycol were comparable with those of split dose. Therefore, same-day dosing with 4 L of polyethylene glycol is a feasible bowel preparation method. See Video Abstract at http://links.lww.com/DCR/B44. COMPARACIÓN DE LA EFICACIA DE LA LIMPIEZA INTESTINAL, LA SEGURIDAD, LA CINÉTICA DEL MOVIMIENTO INTESTINAL Y LA TOLERABILIDAD DEL PACIENTE DE LA PREPARACIÓN INTESTINAL EN EL MISMO DÍA Y EN DOSIS DIVIDIDAS UTILIZANDO 4 L DE POLIETILENGLICOL: UN ESTUDIO PROSPECTIVO ALEATORIZADO: Se recomienda la preparación del intestino en dosis divididas para la colonoscopia de la mañana, aunque un régimen de una sola dosis el mismo día es una alternativa para la colonoscopia en la tarde. La preparación de una sola dosis el mismo día para la colonoscopia matutina rara vez se ha evaluado.Comparamos la eficacia de la limpieza intestinal, la cinética del movimiento intestinal, el perfil de seguridad y la tolerabilidad del paciente de la dosis dividida y la preparación el mismo día utilizando 4 L de polietilenglicol.Este fue un estudio prospectivo, aleatorizado, cegado por el evaluador.Este estudio se realizó en un centro terciario en Corea.Los sujetos del estudio fueron asignados aleatoriamente a el grupo de una dosis en el mismo día o al grupo de dosis dividida. Para el grupo de dosis del mismo día, se ingirieron 4 L de polietilenglicol el día de la colonoscopia a partir de las 5 a.m. para la colonoscopia de la mañana o las 7 a.m. para la colonoscopia de la tarde. En el grupo de dosis dividida, se ingirieron 2 L de polietilenglicol a las 9 p.m. el día anterior a la colonoscopia, y los otros 2 L restantes a partir de las 7 a.m. para la colonoscopia de la mañana o desde las 10 a.m. para la colonoscopia de la tarde. La colonoscopia se realizó a partir de las 10 a.m.La eficacia de la limpieza intestinal se evaluó mediante la escala de preparación intestinal de Boston. Los participantes completaron cuestionarios preguntando sobre los eventos adversos, la cinética del movimiento intestinal y la tolerabilidad de la preparación antes de la colonoscopia.Se incluyeron un total de 339 sujetos (dosis el mismo día, 172; dosis dividida, 167). Un sujeto en cada grupo no se sometió a colonoscopia. La tasa de limpieza exitosa no difirió entre los grupos (dosis el mismo día, 98.8% versus dosis dividida, 98.2%; p = 0.681). No hubo casos de inestabilidad hemodinámica o aspiración en ninguno de los grupos. La tolerabilidad, incluida la satisfacción general y la voluntad de reutilización, fueron comparables entre los grupos.Este fue un estudio de centro único.La eficacia de la limpieza intestinal, el perfil de seguridad y la tolerabilidad de la dosificación en el mismo día con polietilenglicol fueron comparables con los de la dosis dividida. Por lo tanto, la dosificación en el mismo día con 4 L de polietilenglicol es un método factible de preparación intestinal. Vea el video del resumen en http://links.lww.com/DCR/B44.

Efficacy of 1.2 L polyethylene glycol plus ascorbic acid for bowel preparations

BACKGROUND

A low-volume polyethylene glycol (PEG) solution that combines ascorbic acid with PEG-based electrolyte solution (PEG-ASC) is gaining mainstream acceptance for bowel preparation due to reduced volume and improved taste. Although several reports showed that bowel preparation with PEG-ASC volume lower than 2.0 L with laxative agents could be an alternative to traditional preparation regimen, the cleansing protocols have not been fully investigated.

AIM

To evaluate the cleansing efficacy of 1.2 L PEG-ASC solution comparing with 2.0 L PEG electrolyte (PEG-ELS) for bowel preparations.

METHODS

A randomized, single-blinded, open-label, single-center, non-inferiority study was conducted. In total, 312 Japanese adult patients (aged > 18 years) who underwent colonoscopy were enrolled. Patients were randomly allocated to bowel lavage with either 1.2 L of PEG-ASC solution with at least 0.6 L of an additional clear fluid (1.2 L PEG-ASC group) or 2.0 L of PEG-ELS (PEG-ELS group). Then, 48 mg of sennoside was administered at bedtime on the day before colonoscopy, and the designated drug solution was administered at the hospital on the day of colonoscopy. Bowel cleansing was evaluated using the Boston Bowel Preparation Scale (BBPS). The volume of fluid intake and required time for bowel preparation were evaluated. Furthermore, compliance, patient tolerance, and overall acceptability were evaluated using a patient questionnaire, which was assessed using a visual analog scale.

RESULTS

In total, 291 patients (1.2 L PEG-ASC group, 148; PEG-ELS group, 143) completed the study. There was no significant difference in successful cleansing, defined as a BBPS score ≥ 2 in each segment, between the two groups (1.2 L PEG-ASC group, 91.9%; PEG-ELS group, 90.2%; 95%CI: -0.03-0.09). The required time for bowel preparation was significantly shorter (164.95 min ± 68.95 min vs 202.16 min ± 68.69 min, P < 0.001) and the total fluid intake volume was significantly lower (2.23 L ± 0.55 L vs 2.47 L ± 0.56 L, P < 0.001) in the 1.2 L PEG-ASC group than in the PEG-ELS group. Palatability, acceptability of the volume of solution, and overall acceptability evaluated using a patient questionnaire, which was assessed by the visual analog scale, were significantly better in the 1.2 L PEG-ASC group than in the PEG-ELS group (7.70 cm ± 2.57 cm vs 5.80 cm ± 3.24 cm, P < 0.001). No severe adverse event was observed in each group.

CONCLUSION

The 1.2 L PEG-ASC solution was non-inferior to the 2.0 L PEG-ELS solution in terms of cleansing efficacy and had better acceptability among Japanese patients.

Comparable Efficacy of a 1-L PEG and Ascorbic Acid Solution Administered with Bisacodyl versus a 2-L PEG and Ascorbic Acid Solution for Colonoscopy Preparation: A Prospective, Randomized and Investigator-Blinded Trial

BACKGROUND

Two liters of polyethylene glycol (PEG) solution administered with ascorbic acid (Asc) can provide efficacy similar to that of a 4-L PEG solution for colonoscopy preparation. In addition, oral bisacodyl (Bis) has been shown to reduce the volume of PEG needed for a bowel preparation with comparable efficacy. This study aimed to compare the efficacy, tolerability and safety of a 2-L PEG solution mixed with Asc versus the combination of Bis, Asc and a 1-L PEG solution.

METHODS

This was a prospective, randomized, multi-centre, single-blind, non-inferiority trial. Participants who were scheduled for colonoscopy were included and randomized to receive either 2-L PEG and Asc (2L PEG/Asc group) or 1-L PEG, Asc and 20 mg Bis (1L PEG/Asc + Bis group). The quality of bowel preparation was assessed using the Boston Bowel Preparation Scale. Data regarding tolerance, compliance and adverse events were also gathered.

RESULTS

A total of 187 participants were analyzed; 96 were allocated to the 2L PEG/Asc group and 91 to the 1L PEG/Asc + Bis group. Bowel preparation was adequate in 87.5% (84/96) of patients in the 2L PEG/Asc group and 94.5% of the 1L PEG/Asc + Bis group (86/91, p = 0.10). There was no significant difference between the two groups with respect to compliance, tolerability or safety. The patients allocated to the 1L PEG/Asc + Bis group expressed more willingness to repeat the procedure than patients in the 2L PEG/Asc group (p = 0.01).

CONCLUSIONS

Bowel preparation with Bis and a 1-L PEG/Asc solution is as effective, well-tolerated, and safe as a 2-L PEG/Asc solution.

TRIAL REGISTRATION

ClinicalTrials.gov NCT 01745835; Clinical Research Information Service (CRiS) KCT0000708.

Does Polyethylene Glycol (PEG) Plus Ascorbic Acid Induce More Mucosal Injuries than Split-Dose 4-L PEG during Bowel Preparation?

BACKGROUND/AIMS

The aims of this study were to compare the bowel-cleansing efficacy, patient affinity for the preparation solution, and mucosal injury between a split dose of polyethylene glycol (SD-PEG) and low-volume PEG plus ascorbic acid (LV-PEG+Asc) in outpatient scheduled colonoscopies.

METHODS

Of the 319 patients, 160 were enrolled for SDPEG, and 159 for LV-PEG+Asc. The bowel-cleansing efficacy was rated according to the Ottawa bowel preparation scale. Patient affinity for the preparation solution was assessed using a questionnaire. All mucosal injuries observed during colonoscopy were biopsied and histopathologically reviewed.

RESULTS

There was no significant difference in bowel cleansing between the groups. The LV-PEG+Asc group reported better patient acceptance and preference. There were no significant differences in the incidence or characteristics of the mucosal injuries between the two groups.

CONCLUSIONS

Compared with SD-PEG, LV-PEG+Asc exhibited equivalent bowel-cleansing efficacy and resulted in improved patient acceptance and preference. There was no significant difference in mucosal injury between SD-PEG and LV-PEG+Asc. Thus, the LV-PEG+Asc preparation could be used more effectively and easily for routine colonoscopies without risking significant mucosal injury.