Digestive Endoscopy 2014; 26: 731–736
doi: 10.1111/den.12265
Original Article
Efficacy and tolerability of low-volume (2 L) versus single(4 L) versus split-dose (2 L + 2 L) polyethylene glycol bowel preparation for colonoscopy: Randomized clinical trial Félix I. Téllez-Ávila,1 Enrique Murcio-Pérez,1 Angela Saúl,1 Salvador Herrera-Gómez,1 Francisco Valdovinos-Andraca,1 Victor Acosta-Nava,2 Rafael Barreto1 and Javier Elizondo-Rivera1 Departments of 1Endoscopy and 2Anesthesiology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Mexico City, Mexico Background and Aim: To compare the efficacy and tolerability of a low-volume (2-L) polyethylene glycol (PEG) regimen for colonoscopy compared to single (4-L) or split-dose (2-L + 2-L) regimens. Methods: In-hospital patients who were candidates for colonoscopy were randomly assigned to: group 1 single-dose (PEG 4 L the day before the study, n = 60); group 2: split-dose (2 L the day before and 2 L on the day of the procedure, n = 61); and group 3: low-volume 2-L PEG solution (the day of the procedure, n = 59). A blinded evaluation of the quality of colonic preparation was assessed by the Boston bowel preparation scale. Results: Satisfactory bowel preparation of the right colon was
Conclusions: Preparation with 2 L caused less abdominal discomfort and fewer sleep disorders. The split dose had a better quality of preparation in the right colon. Both preparations were clearly better than the 4-L preparation.
more frequently reported for group 3 than for group 1 (70% vs 53%, P = 0.045), in the transverse colon it was 82% versus 69%
Key words: Boston bowel preparation scale, bowel preparation, colonoscopy, polyethylene glycol, polyp
INTRODUCTION
frequently satisfactory with 2-L PEG than with 4-L PEG (54% vs 82% of patients, respectively; P < 0.0001) and when the entire preparation was given the day before.2 The aim of the present study was to test the efficacy and tolerability of a low-volume (2-L) PEG regimen for colonoscopy compared to single (4-L) or split-dose (2-L + 2-L) treatments.
A
DEQUATE BOWEL CLEANSING is an important determinant of the efficacy of colonoscopy. Polyethylene glycol (PEG)-based solutions are used commonly in bowel preparation, but their poor palatability and large volumes (4 L) influence compliance. Therefore, split dosing is the recommended preparation. Various combinations of low-volume (2-L) PEG with an additional laxative have been tested.1 In 11 randomized controlled trials (RCT) (total of 1997 patients) no significant difference was found between the low-volume formulation and 4-L PEG in terms of colon cleanliness for the whole colon.1–12 However, cleanliness in the right colon (assessed in a single study) was less Corresponding: Félix I. Téllez-Ávila, Department of Endoscopy, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga #15. Col. Sección XVI. Del. Tlalpan, Mexico City 14000, Mexico. Email: [email protected] Received 20 November 2013; accepted 29 January 2014.
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(P = 0.032), and on the left side of the colon it was 80% versus 67.7% (P = 0.028). Compared to group 2, satisfactory bowel preparation in group 3 was similar in the transverse colon and left colon. Nausea, vomiting, and abdominal discomfort were less frequent in patients of group 3. Patients in group 3 had fewer sleep disorders and fewer hours of sleep loss compared to patients in the other groups.
METHODS
A
PROSPECTIVE RANDOMIZED TRIAL was conducted in a single tertiary institution. The protocol was reviewed and accepted by the Institution’s Ethics Committee and registered in ClinicalTrials.gov with number NCT01929590. All authors had access to the study data and approved the final version of the manuscript. Exclusion criteria included patients under 18 years of age, the presence of a severe illness (cardiac, renal, or metabolic), major psychiatric illness, known allergies to PEG, a history of any largebowel resection surgery or refusal to consent to the study.
© 2014 The Authors Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society
731
732
F. I. Téllez-Ávila et al.
In-hospital patients seen from October 2011 to June 2012 were randomly assigned to one of three groups: group 1 single dose (PEG-3350; PEG 4 L the day before the study, starting at 17:00 and finishing at 21:00 h); group 2: splitdose (PEG-3350; 2 L the day before 17:00–19:00 h and 2 L the day of the procedure 06:00–08:00 h); group 3: lowvolume 2 L PEG solution (the day of the procedure 06:00– 08:00 h). After providing informed consent, the patients were provided written instructions on either of the three bowel preparations in a closed opaque envelope by a member of the investigation team. This individual was a different physician to their respective endoscopist and was blinded to the contents of the envelope. The envelopes were randomized (by using a computer-generated random numbers table) by an independent investigator who did not disclose the randomization key until the last patient had been included. A different physician, blinded to the bowel preparation used for each patient, made an evaluation regarding the quality of colonic preparation. All colonoscopies were carried out not earlier than 3 h after the last dose of bowel preparation. The preparation for intestinal cleaning was made by giving PEG-3350: sodium bicarbonate (1.43 g), sodium chloride (2.80 g), potassium chloride (0.37 g), bicarbonate (17.0 mEq/L), chloride (53.0 mEq/L), sodium (65.0 mEq/ L), and potassium (5.0 mEq/L) (Nulytely; Asofarma de México, Mexico City, Mexico) as follows. One sachet diluted in 1 L drinking water per hour; the final quantity was prepared according to the designated study group. Colonoscopy was carried out under conscious sedation by a specialist in anesthesiology, with the presence of continuous monitoring of vital signs, oxygen saturation and electrocardiogram tracing, with supplemental oxygen managed using a standard preparation that was conducted independently of the present study. We carried out the colonoscopy procedure according to standard recommendations, emphasizing the duration of at least 7 min during the withdrawal maneuver. A doctor trained to carry out colonoscopies and overcome the learning curve according to international recommendations carried out all procedures. Colonoscopy was carried out with standard equipment (CFQ 140–180 L; Olympus, Center Valley, PA, USA). The scope was advanced until the cecum was identified by the anatomical characteristics (ileocecal valve, appendicular orifice and tapeworm colonic junction). During the withdrawal, all colonic segments were assessed (cecum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum) over a period of no less than 7 min. The quality of colonic preparation was assessed by the Boston bowel preparation scale.13 Tolerability (nausea, vomiting, and abdominal pain), compliance, sleep disturbance and adverse effects in group 3 were compared with those in
Digestive Endoscopy 2014; 26: 731–736
groups 1 and 2. Sleep disturbance (hours of sleep loss) as a result of the use of the PEG solution was evaluated with a dichotomous response. Sleep loss was evaluated with the following questions to patients: ‘At what time do you go to sleep regularly?’ and ‘At what time did you go to sleep the night before the colonoscopy?’. The difference was considered as the time of sleep loss. Time since last dose of bowel-preparation agent, time since last solid food was consumed, approximate amount of bowel preparation taken (0%, 25%, 75%, or 100%), and start time of colonoscopy were also recorded. Satisfactory colon preparation was considered when Boston bowel preparation scale scores were 2/3; otherwise, the bowel preparation procedure was considered unsatisfactory.
Statistical analysis and sample size Demographic and clinical characteristics were summarized with means, medians, and standard deviations. To assess differences between groups, data were analyzed with Mann– Whitney U-test, Student’s t-test and χ2-test according to the variables evaluated. Differences between groups regarding the quality of colonic preparation (considered as satisfactory [2/3 points on Boston scale] vs inadequate [0/1 points on Boston scale]) were analyzed with the χ2-test. P-value (α) 8≤ 14 h (%)
C† ≥14 h (%)
P-value A vs B
P-value A vs C
83.1 91 91
63 75 75
54 73 76
0.15 0.19 0.19
0.007 0.04 0.07
†
Duration of the interval (‘hours between’) between the completion of bowel preparation and the start of colonoscopy. Satisfactory colon preparation was considered when scores of the Boston bowel preparation scale were 2/3.
‡
the answer regarding the Hispanic population. Another interesting study by Longcroft-Wheaton and Bhandari comparing two sachets of sodium picosulfate on the morning of the procedure versus split dosing with the same solution shows that perhaps more important than the type and amount of solution used for colon cleansing is adequate timing as the key to obtaining the ideal colon-cleansing effect.17 Moreover, according to these results, the benefit of the initial 2 L the day before the procedure can be questioned. The low-volume scheme, with 2 L of solution, has been scarcely evaluated and seems to have better acceptance with good results in the quality of the preparation.2,6,7 Our results support the fact that the low-volume preparation solution provides better results compared to preparations of 4 L, and results that are very similar to the split-dose regimen with regard to the quality of the preparation in the transverse colon and left colon, although there was a trend to favoring the latter in the right colon (Table 2). The low-volume preparation has a better performance to the split-dose in relation to sleep loss. We believe that the option with 2 L is adequate in a group of patients who may have a poor attachment to larger amounts of liquid, such as elderly patients. The good results obtained at low volumes appear to be related to the time interval between the last part of the preparation and the start of colonoscopy (group 3 vs group 1 : 4 [2–7] vs 15 [3.6–19] hours [P = 0.001] and group 3 vs group 2 : 4 [2–7] vs 4 [2.5–18] hours [P = 0.73]) (Table 3). In the present study, we classified the quality of bowel preparation as satisfactory (Boston bowel preparation scale score 2 and 3) and unsatisfactory (Boston bowel preparation scale score 0–1) for a simple and clear analysis of the factors affecting bowel preparation quality. In our opinion, the Boston bowel preparation scale is a valid and reliable bowelpreparation rating scale that can be easily remembered and has previously demonstrated good intraobserver and interobserver reliability among physicians, including both fellows and attending physicians.13,18 Our study has some limitations. First, it was limited to a single institution, thereby potentially limiting the generalizability of the results. Because of logistical difficulties in our
city, it is very difficult to include outpatients to undergo bowel preparation and transfer them to the hospital on the same day. However, it is interesting that this was done in a hospitalized population, which makes our study unique and allowed us to have better control regarding the diet of the patients. Our study also differs from previous studies in the lack of any additional laxative. Most 2-L preparations that have been used in previous studies included magnesium citrate or another laxative. It is possible that additional laxative on the day before might be helpful to clean up the entire colon; however, the possibility of a negative impact regarding the advantages of same-day preparation in relationship to sleep disorders and hours of sleep lost must be considered. Future studies comparing schemes of low-volume preparations with and without additional laxative seem necessary. In conclusion, preparation with a low-volume (2-L) preparation resulted in less abdominal discomfort, fewer patients with sleep disorders and fewer hours of sleep lost. The split dose provided a better quality of preparation in the right colon, a higher rate of complete colonoscopies and a higher rate of polyp detection. Both preparations (split-dose and low-volume) were clearly better to the preparation involving 4 L on the day prior to the study.
CONFLICT OF INTERESTS
A
UTHORS DECLARE NO conflict of interests for this article. This work was supported, in part, by Asofarma de México, México.
REFERENCES 1 Hassan C, Bretthauer M, Kaminski MF et al. European Society of Gastrointestinal Endoscopy. Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) guideline. Endoscopy 2013; 45: 142–50. 2 Corporaal S, Kleibeuker JH, Koornstra JJ. Low-volume PEG plus ascorbic acid versus high-volume PEG as bowel preparation for colonoscopy. Scand. J. Gastroenterol. 2010; 45: 1380–6.
© 2014 The Authors Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society
736
F. I. Téllez-Ávila et al.
3 Adams WJ, Meagher AP, Lubowski DZ, King DW. Bisacodyl reduces the volume of polyethylene glycol solution required for bowel preparation. Dis. Colon Rectum 1994; 37: 229–33. 4 Jansen SV, Goedhard JG, Winkens B, van Deursen CT. Preparation before colonoscopy: A randomized controlled trial comparing different regimes. Eur. J. Gastroenterol. Hepatol. 2011; 23: 897–902. 5 Marmo R, Rotondano G, Riccio G et al. Effective bowel cleansing before colonoscopy: A randomized study of split-dosage versus non-split dosage regimens of high-volume versus lowvolume polyethylene glycol solutions. Gastrointest. Endosc. 2010; 72: 313–20. 6 Pontone S, Angelini R, Standoli M et al. Low-volume plus ascorbic acid versus high-volume plus simethicone bowel preparation before colonoscopy. World J. Gastroenterol. 2011; 17: 4689–95. 7 Ell C, Fischbach W, Bronisch HJ et al. Randomized trial of low-volume PEG solution versus standard PEG + electrolytes for bowel cleansing before colonoscopy. Am. J. Gastroenterol. 2008; 103: 883–93. 8 Abut E, Guveli H, Yasar B et al. Administration of olive oil followed by a low volume of polyethylene glycol-electrolyte lavage solution improves patient satisfaction with right-side colonic cleansing over administration of the conventional volume of polyethylene glycol-electrolyte lavage solution for colonoscopy preparation. Gastrointest. Endosc. 2009; 70: 515–21. 9 Enestvedt BK, Fennerty MB, Eisen GM. Randomised clinical trial: MiraLAX versus Golytely – a controlled study of efficacy and patient tolerability in bowel preparation for colonoscopy. Aliment. Pharmacol. Ther. 2011; 33: 33–40. 10 Haapamaki MM, Lindstrom M, Sandzen B. Low-volume bowel preparation is inferior to standard 4 L polyethylene glycol. Surg. Endosc. 2011; 25: 897–901.
Digestive Endoscopy 2014; 26: 731–736
11 DiPalma JA, McGowan J, Cleveland MV. Clinical trial: An efficacy evaluation of reduced bisacodyl given as part of a polyethylene glycol electrolyte solution preparation prior to colonoscopy. Aliment. Pharmacol. Ther. 2007; 26: 1113–9. 12 Hookey LC, Depew WT, Vanner SJ. Combined low volume polyethylene glycol solution plus stimulant laxatives versus standard volume polyethylene glycol solution: A prospective, randomized study of colon cleansing before colonoscopy. Can. J. Gastroenterol. 2006; 20: 101–5. 13 Lai EJ, Calderwood AH, Doros G, Fix OK, Jacobson BC. The Boston bowel preparation scale: A valid and reliable instrument for colonoscopy-oriented research. Gastrointest. Endosc. 2009; 69: 620–5. 14 Siddiqui AA, Yang K, Spechler SJ et al. Duration of the interval between the completion of bowel preparation and the start of colonoscopy predicts bowel-preparation quality. Gastrointest. Endosc. 2009; 69: 700–6. 15 Seo EH, Kim TO, Park MJ et al. Optimal preparation-tocolonoscopy interval in split-dose PEG bowel preparation determines satisfactory bowel preparation quality: An observational prospective study. Gastrointest. Endosc. 2012; 75: 583–90. 16 Chiu HM, Lin JT, Wang HP et al. The impact of colon preparation timing on colonoscopy detection of colorectal neoplasms– A prospective endoscopist-blinded randomized trial. Am. J. Gastroenterol. 2006; 101: 2719–25. 17 Longcroft-Wheaton G, Bhandari P. Same-day bowel cleansing regimen is superior to a split-dose regimen over two days for afternoon colonoscopy results from a large prospective series. J. Clin. Gastroenterol. 2012; 46: 57–61. 18 Calderwood AH, Jacobson BC. Comprehensive validation of the Boston bowel preparation scale. Gastrointest. Endosc. 2010; 72: 686–92.
© 2014 The Authors Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society
doi: 10.1111/den.12265
Original Article
Efficacy and tolerability of low-volume (2 L) versus single(4 L) versus split-dose (2 L + 2 L) polyethylene glycol bowel preparation for colonoscopy: Randomized clinical trial Félix I. Téllez-Ávila,1 Enrique Murcio-Pérez,1 Angela Saúl,1 Salvador Herrera-Gómez,1 Francisco Valdovinos-Andraca,1 Victor Acosta-Nava,2 Rafael Barreto1 and Javier Elizondo-Rivera1 Departments of 1Endoscopy and 2Anesthesiology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Mexico City, Mexico Background and Aim: To compare the efficacy and tolerability of a low-volume (2-L) polyethylene glycol (PEG) regimen for colonoscopy compared to single (4-L) or split-dose (2-L + 2-L) regimens. Methods: In-hospital patients who were candidates for colonoscopy were randomly assigned to: group 1 single-dose (PEG 4 L the day before the study, n = 60); group 2: split-dose (2 L the day before and 2 L on the day of the procedure, n = 61); and group 3: low-volume 2-L PEG solution (the day of the procedure, n = 59). A blinded evaluation of the quality of colonic preparation was assessed by the Boston bowel preparation scale. Results: Satisfactory bowel preparation of the right colon was
Conclusions: Preparation with 2 L caused less abdominal discomfort and fewer sleep disorders. The split dose had a better quality of preparation in the right colon. Both preparations were clearly better than the 4-L preparation.
more frequently reported for group 3 than for group 1 (70% vs 53%, P = 0.045), in the transverse colon it was 82% versus 69%
Key words: Boston bowel preparation scale, bowel preparation, colonoscopy, polyethylene glycol, polyp
INTRODUCTION
frequently satisfactory with 2-L PEG than with 4-L PEG (54% vs 82% of patients, respectively; P < 0.0001) and when the entire preparation was given the day before.2 The aim of the present study was to test the efficacy and tolerability of a low-volume (2-L) PEG regimen for colonoscopy compared to single (4-L) or split-dose (2-L + 2-L) treatments.
A
DEQUATE BOWEL CLEANSING is an important determinant of the efficacy of colonoscopy. Polyethylene glycol (PEG)-based solutions are used commonly in bowel preparation, but their poor palatability and large volumes (4 L) influence compliance. Therefore, split dosing is the recommended preparation. Various combinations of low-volume (2-L) PEG with an additional laxative have been tested.1 In 11 randomized controlled trials (RCT) (total of 1997 patients) no significant difference was found between the low-volume formulation and 4-L PEG in terms of colon cleanliness for the whole colon.1–12 However, cleanliness in the right colon (assessed in a single study) was less Corresponding: Félix I. Téllez-Ávila, Department of Endoscopy, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga #15. Col. Sección XVI. Del. Tlalpan, Mexico City 14000, Mexico. Email: [email protected] Received 20 November 2013; accepted 29 January 2014.
bs_bs_banner
(P = 0.032), and on the left side of the colon it was 80% versus 67.7% (P = 0.028). Compared to group 2, satisfactory bowel preparation in group 3 was similar in the transverse colon and left colon. Nausea, vomiting, and abdominal discomfort were less frequent in patients of group 3. Patients in group 3 had fewer sleep disorders and fewer hours of sleep loss compared to patients in the other groups.
METHODS
A
PROSPECTIVE RANDOMIZED TRIAL was conducted in a single tertiary institution. The protocol was reviewed and accepted by the Institution’s Ethics Committee and registered in ClinicalTrials.gov with number NCT01929590. All authors had access to the study data and approved the final version of the manuscript. Exclusion criteria included patients under 18 years of age, the presence of a severe illness (cardiac, renal, or metabolic), major psychiatric illness, known allergies to PEG, a history of any largebowel resection surgery or refusal to consent to the study.
© 2014 The Authors Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society
731
732
F. I. Téllez-Ávila et al.
In-hospital patients seen from October 2011 to June 2012 were randomly assigned to one of three groups: group 1 single dose (PEG-3350; PEG 4 L the day before the study, starting at 17:00 and finishing at 21:00 h); group 2: splitdose (PEG-3350; 2 L the day before 17:00–19:00 h and 2 L the day of the procedure 06:00–08:00 h); group 3: lowvolume 2 L PEG solution (the day of the procedure 06:00– 08:00 h). After providing informed consent, the patients were provided written instructions on either of the three bowel preparations in a closed opaque envelope by a member of the investigation team. This individual was a different physician to their respective endoscopist and was blinded to the contents of the envelope. The envelopes were randomized (by using a computer-generated random numbers table) by an independent investigator who did not disclose the randomization key until the last patient had been included. A different physician, blinded to the bowel preparation used for each patient, made an evaluation regarding the quality of colonic preparation. All colonoscopies were carried out not earlier than 3 h after the last dose of bowel preparation. The preparation for intestinal cleaning was made by giving PEG-3350: sodium bicarbonate (1.43 g), sodium chloride (2.80 g), potassium chloride (0.37 g), bicarbonate (17.0 mEq/L), chloride (53.0 mEq/L), sodium (65.0 mEq/ L), and potassium (5.0 mEq/L) (Nulytely; Asofarma de México, Mexico City, Mexico) as follows. One sachet diluted in 1 L drinking water per hour; the final quantity was prepared according to the designated study group. Colonoscopy was carried out under conscious sedation by a specialist in anesthesiology, with the presence of continuous monitoring of vital signs, oxygen saturation and electrocardiogram tracing, with supplemental oxygen managed using a standard preparation that was conducted independently of the present study. We carried out the colonoscopy procedure according to standard recommendations, emphasizing the duration of at least 7 min during the withdrawal maneuver. A doctor trained to carry out colonoscopies and overcome the learning curve according to international recommendations carried out all procedures. Colonoscopy was carried out with standard equipment (CFQ 140–180 L; Olympus, Center Valley, PA, USA). The scope was advanced until the cecum was identified by the anatomical characteristics (ileocecal valve, appendicular orifice and tapeworm colonic junction). During the withdrawal, all colonic segments were assessed (cecum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum) over a period of no less than 7 min. The quality of colonic preparation was assessed by the Boston bowel preparation scale.13 Tolerability (nausea, vomiting, and abdominal pain), compliance, sleep disturbance and adverse effects in group 3 were compared with those in
Digestive Endoscopy 2014; 26: 731–736
groups 1 and 2. Sleep disturbance (hours of sleep loss) as a result of the use of the PEG solution was evaluated with a dichotomous response. Sleep loss was evaluated with the following questions to patients: ‘At what time do you go to sleep regularly?’ and ‘At what time did you go to sleep the night before the colonoscopy?’. The difference was considered as the time of sleep loss. Time since last dose of bowel-preparation agent, time since last solid food was consumed, approximate amount of bowel preparation taken (0%, 25%, 75%, or 100%), and start time of colonoscopy were also recorded. Satisfactory colon preparation was considered when Boston bowel preparation scale scores were 2/3; otherwise, the bowel preparation procedure was considered unsatisfactory.
Statistical analysis and sample size Demographic and clinical characteristics were summarized with means, medians, and standard deviations. To assess differences between groups, data were analyzed with Mann– Whitney U-test, Student’s t-test and χ2-test according to the variables evaluated. Differences between groups regarding the quality of colonic preparation (considered as satisfactory [2/3 points on Boston scale] vs inadequate [0/1 points on Boston scale]) were analyzed with the χ2-test. P-value (α) 8≤ 14 h (%)
C† ≥14 h (%)
P-value A vs B
P-value A vs C
83.1 91 91
63 75 75
54 73 76
0.15 0.19 0.19
0.007 0.04 0.07
†
Duration of the interval (‘hours between’) between the completion of bowel preparation and the start of colonoscopy. Satisfactory colon preparation was considered when scores of the Boston bowel preparation scale were 2/3.
‡
the answer regarding the Hispanic population. Another interesting study by Longcroft-Wheaton and Bhandari comparing two sachets of sodium picosulfate on the morning of the procedure versus split dosing with the same solution shows that perhaps more important than the type and amount of solution used for colon cleansing is adequate timing as the key to obtaining the ideal colon-cleansing effect.17 Moreover, according to these results, the benefit of the initial 2 L the day before the procedure can be questioned. The low-volume scheme, with 2 L of solution, has been scarcely evaluated and seems to have better acceptance with good results in the quality of the preparation.2,6,7 Our results support the fact that the low-volume preparation solution provides better results compared to preparations of 4 L, and results that are very similar to the split-dose regimen with regard to the quality of the preparation in the transverse colon and left colon, although there was a trend to favoring the latter in the right colon (Table 2). The low-volume preparation has a better performance to the split-dose in relation to sleep loss. We believe that the option with 2 L is adequate in a group of patients who may have a poor attachment to larger amounts of liquid, such as elderly patients. The good results obtained at low volumes appear to be related to the time interval between the last part of the preparation and the start of colonoscopy (group 3 vs group 1 : 4 [2–7] vs 15 [3.6–19] hours [P = 0.001] and group 3 vs group 2 : 4 [2–7] vs 4 [2.5–18] hours [P = 0.73]) (Table 3). In the present study, we classified the quality of bowel preparation as satisfactory (Boston bowel preparation scale score 2 and 3) and unsatisfactory (Boston bowel preparation scale score 0–1) for a simple and clear analysis of the factors affecting bowel preparation quality. In our opinion, the Boston bowel preparation scale is a valid and reliable bowelpreparation rating scale that can be easily remembered and has previously demonstrated good intraobserver and interobserver reliability among physicians, including both fellows and attending physicians.13,18 Our study has some limitations. First, it was limited to a single institution, thereby potentially limiting the generalizability of the results. Because of logistical difficulties in our
city, it is very difficult to include outpatients to undergo bowel preparation and transfer them to the hospital on the same day. However, it is interesting that this was done in a hospitalized population, which makes our study unique and allowed us to have better control regarding the diet of the patients. Our study also differs from previous studies in the lack of any additional laxative. Most 2-L preparations that have been used in previous studies included magnesium citrate or another laxative. It is possible that additional laxative on the day before might be helpful to clean up the entire colon; however, the possibility of a negative impact regarding the advantages of same-day preparation in relationship to sleep disorders and hours of sleep lost must be considered. Future studies comparing schemes of low-volume preparations with and without additional laxative seem necessary. In conclusion, preparation with a low-volume (2-L) preparation resulted in less abdominal discomfort, fewer patients with sleep disorders and fewer hours of sleep lost. The split dose provided a better quality of preparation in the right colon, a higher rate of complete colonoscopies and a higher rate of polyp detection. Both preparations (split-dose and low-volume) were clearly better to the preparation involving 4 L on the day prior to the study.
CONFLICT OF INTERESTS
A
UTHORS DECLARE NO conflict of interests for this article. This work was supported, in part, by Asofarma de México, México.
REFERENCES 1 Hassan C, Bretthauer M, Kaminski MF et al. European Society of Gastrointestinal Endoscopy. Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) guideline. Endoscopy 2013; 45: 142–50. 2 Corporaal S, Kleibeuker JH, Koornstra JJ. Low-volume PEG plus ascorbic acid versus high-volume PEG as bowel preparation for colonoscopy. Scand. J. Gastroenterol. 2010; 45: 1380–6.
© 2014 The Authors Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society
736
F. I. Téllez-Ávila et al.
3 Adams WJ, Meagher AP, Lubowski DZ, King DW. Bisacodyl reduces the volume of polyethylene glycol solution required for bowel preparation. Dis. Colon Rectum 1994; 37: 229–33. 4 Jansen SV, Goedhard JG, Winkens B, van Deursen CT. Preparation before colonoscopy: A randomized controlled trial comparing different regimes. Eur. J. Gastroenterol. Hepatol. 2011; 23: 897–902. 5 Marmo R, Rotondano G, Riccio G et al. Effective bowel cleansing before colonoscopy: A randomized study of split-dosage versus non-split dosage regimens of high-volume versus lowvolume polyethylene glycol solutions. Gastrointest. Endosc. 2010; 72: 313–20. 6 Pontone S, Angelini R, Standoli M et al. Low-volume plus ascorbic acid versus high-volume plus simethicone bowel preparation before colonoscopy. World J. Gastroenterol. 2011; 17: 4689–95. 7 Ell C, Fischbach W, Bronisch HJ et al. Randomized trial of low-volume PEG solution versus standard PEG + electrolytes for bowel cleansing before colonoscopy. Am. J. Gastroenterol. 2008; 103: 883–93. 8 Abut E, Guveli H, Yasar B et al. Administration of olive oil followed by a low volume of polyethylene glycol-electrolyte lavage solution improves patient satisfaction with right-side colonic cleansing over administration of the conventional volume of polyethylene glycol-electrolyte lavage solution for colonoscopy preparation. Gastrointest. Endosc. 2009; 70: 515–21. 9 Enestvedt BK, Fennerty MB, Eisen GM. Randomised clinical trial: MiraLAX versus Golytely – a controlled study of efficacy and patient tolerability in bowel preparation for colonoscopy. Aliment. Pharmacol. Ther. 2011; 33: 33–40. 10 Haapamaki MM, Lindstrom M, Sandzen B. Low-volume bowel preparation is inferior to standard 4 L polyethylene glycol. Surg. Endosc. 2011; 25: 897–901.
Digestive Endoscopy 2014; 26: 731–736
11 DiPalma JA, McGowan J, Cleveland MV. Clinical trial: An efficacy evaluation of reduced bisacodyl given as part of a polyethylene glycol electrolyte solution preparation prior to colonoscopy. Aliment. Pharmacol. Ther. 2007; 26: 1113–9. 12 Hookey LC, Depew WT, Vanner SJ. Combined low volume polyethylene glycol solution plus stimulant laxatives versus standard volume polyethylene glycol solution: A prospective, randomized study of colon cleansing before colonoscopy. Can. J. Gastroenterol. 2006; 20: 101–5. 13 Lai EJ, Calderwood AH, Doros G, Fix OK, Jacobson BC. The Boston bowel preparation scale: A valid and reliable instrument for colonoscopy-oriented research. Gastrointest. Endosc. 2009; 69: 620–5. 14 Siddiqui AA, Yang K, Spechler SJ et al. Duration of the interval between the completion of bowel preparation and the start of colonoscopy predicts bowel-preparation quality. Gastrointest. Endosc. 2009; 69: 700–6. 15 Seo EH, Kim TO, Park MJ et al. Optimal preparation-tocolonoscopy interval in split-dose PEG bowel preparation determines satisfactory bowel preparation quality: An observational prospective study. Gastrointest. Endosc. 2012; 75: 583–90. 16 Chiu HM, Lin JT, Wang HP et al. The impact of colon preparation timing on colonoscopy detection of colorectal neoplasms– A prospective endoscopist-blinded randomized trial. Am. J. Gastroenterol. 2006; 101: 2719–25. 17 Longcroft-Wheaton G, Bhandari P. Same-day bowel cleansing regimen is superior to a split-dose regimen over two days for afternoon colonoscopy results from a large prospective series. J. Clin. Gastroenterol. 2012; 46: 57–61. 18 Calderwood AH, Jacobson BC. Comprehensive validation of the Boston bowel preparation scale. Gastrointest. Endosc. 2010; 72: 686–92.
© 2014 The Authors Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society
