Published online Feb 16, 2013. doi: 10.4253/wjge.v5.i2.39
Revised: October 8, 2012
Accepted: December 1, 2012
Published online: February 16, 2013
Recent technological advances in colonoscopy have led to improvements in both image enhancement and procedural performance. However, the utility of these technological advancements remain dependent on the quality of bowel preparation during colonoscopy. Poor bowel preparation has been shown to be associated with lower quality indicators of colonoscopy performance, such as reduced cecal intubation rates, increased patient discomfort and lower adenoma detection. The most popular bowel preparation regimes currently used are based on either Polyethylene glycol-electrolyte, a non-absorbable solution, or aqueous sodium phosphate, a low-volume hyperosmotic solution. Statements from various international societies and several reviews have suggested that the efficacy of bowel preparation regimes based on both purgatives are similar, although patients’ compliance with these regimes may differ somewhat. Many studies have now shown that factors other than the type of bowel preparation regime used, can influence the quality of bowel preparation among adult patients undergoing colonoscopy. These factors can be broadly categorized as either patient-related or procedure-related. Studies from both Asia and the West have identified patient-related factors such as an increased age, male gender, presence of co-morbidity and socio-economic status of patients to be associated with poor bowel preparation among adults undergoing routine out-patient colonoscopy. Additionally, procedure-related factors such as adherence to bowel preparation instructions, timing of bowel purgative administration and appointment waiting times for colonoscopy are recognized to influence the quality of colon cleansing. Knowledge of these factors should aid clinicians in modifying bowel preparation regimes accordingly, such that the quality of colonoscopy performance and delivery of service to patients can be optimised.
- Citation: Romero RV, Mahadeva S. Factors influencing quality of bowel preparation for colonoscopy. World J Gastrointest Endosc 2013; 5(2): 39-46
- URL: https://www.wjgnet.com/1948-5190/full/v5/i2/39.htm
- DOI: https://dx.doi.org/10.4253/wjge.v5.i2.39
Colorectal cancer (CRC) is recognized as a significant health problem in both developed and developing countries. In 2008, the worldwide estimated number of new cases of colorectal cancers was 1 233 000 with an estimated mortality of 608 700[1]. In Asia, the incidence of colorectal cancer has been noted to be increasing and is already comparable to that of the West[2-5]. However, if diagnosed at an early stage, CRC is one of the most preventable and curable malignancies[6]. Therefore, screening with the ideal modality can potentially alleviate the health burden of CRC[7,8]. Current recommendations on colorectal screening advocate colonoscopy as the preferred modality[9,10], in view of its’ accuracy in detecting early lesions and proven efficacy in lowering rates of incident CRC[11-14]. Advances in technology, such as magnification lenses, narrow band imaging and chromoendoscopy have increased the detection yield for early cancers during colonoscopy[15-17]. Lesions characterized as early cancers can be endoscopically resected at the same sitting and can be curative[18,19]. However, the advantages of colonoscopy are not only limited to the detection and treatment of early cancers. Other therapeutic benefits of colonoscopy include endoscopic hemostasis of bleeding lesions, dilatation of benign strictures and stenting of malignant strictures[20-23].
Despite these advances in diagnostic and therapeutic colonoscopy, the utility of colonoscopy remains dependent on the cleanliness of the colon or the quality of bowel preparation. For instance, adenoma detection rate, being one of the quality indicators of colonoscopy, is recognized to be decreased by poor bowel preparation[24-26]. Colonoscopy performance is also significantly affected by poor bowel preparation. In a recent study among Asian patients, poor bowel preparation resulted in decreased cecal intubation, prolonged cecal intubation and total colonoscopy time, and increased patient discomfort[27]. In similar studies in Europe and Australia, poorly prepared patients during colonoscopy had longer, more difficult procedures and a lower diagnostic yield for polyps[28-30].
Many clinical studies have used the terms ‘‘excellent’’, ‘‘good’’, ‘‘fair’’, and ‘‘poor’’ to rate the quality of bowel preparation[31-34]. ‘‘Excellent’’ is typically defined as no or minimal solid stool and only small amounts of clear fluid that require suctioning. ‘‘Good’’ is typically used to describe no or minimal solid stool with large amounts of clear fluid that require suctioning. ‘‘Fair’’ generally refers to collections of semisolid debris that are cleared with difficulty. ‘‘Poor’’ generally refers to solid or semisolid debris that cannot be cleared effectively. For practical purposes, an unsatisfactory or inadequate bowel preparation is one which would use a combination of the descriptions of “fair” and “poor”.
Several colon cleansing agents and schedules have been utilized and studied for bowel preparation during colonoscopy. The most popular regimes today are based on either polyethylene glycol-electrolyte (PEG) lavage solution or aqueous sodium phosphate solution[35-38]. PEG is a non-absorbable solution that should pass through the bowel without net absorption or secretion[39]. Significant fluid and electrolyte shifts are therefore avoided but large volumes (4 L) are still required to achieve a cathartic effect. Sulphate-free PEG (SF-PEG) is more palatable with improved aroma and taste than pure PEG solutions. A reduced-volume (2 L) preparations coupled with irritant laxatives, such as bisacodyl or magnesium citrate[40], was developed to increase patient compliance and is recognised to be as effective as the standard 4 L PEG preparation[41-43]. Aqueous sodium phosphate is a low-volume hyperosmotic solution which contains 48 g (400 mmol) of monobasic sodium phosphate and 18 g (130 mmol) of dibasic sodium phosphate per 100 mL. Sodium phosphate osmotically draws plasma water into the bowel lumen to promote colonic cleansing and significant fluid and electrolyte shifts can occur[39]. Two meta analyses, comprising 71 trials (10 201 subjects) and 18 trials (2792 subjects) respectively, previously concluded that sodium phosphate-based bowel preparations resulted in a more complete and better quality of bowel preparation compared to 4-L PEG[44,45], mainly due to the poorer compliance with the latter[46-49]. However, sodium phosphate is associated with significant fluid and electrolyte shifts due to its hyperosmotic nature and patients with renal impairment, dehydration, on angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers can develop renal failure[50-52].
The recent American Society for Gastrointestinal Endoscopy, American Society of Colon and Rectal Surgeons, and the Society of American Gastrointestinal and Endoscopic Surgeons consensus statements on bowel preparation evaluated the use of PEG, SF-PEG, low-volume PEG/PEG-3350 with bisacodyl delayed-release tablets, aqueous and tablet preparations of sodium phosphate, the data of which has been summarised in Table 1[50]. There is little variation in bowel preparation regimens in other countries. The European Society of Gastrointestinal Endoscopy recommended 4 L polyethylene glycol with low-dose sodium phosphate boosts as bowel preparation for colon capsule endoscopy[53]. Similarly in a bowel preparation study in South Korea, subjects were given PEG solutions in 4 L of water[54]. In Canada, as described in the position paper of the Canadian Association of Gastroenterology, the most commonly used bowel preparation agents are polyethylene glycol, sodium phosphate, magnesium citrate, and sodium picosulfate, citric acid, and magnesium oxide-containing solutions[55]. In a colonoscopy practice study in the United Kingdom comprising of 9223 colonoscopies, bowel preparation was performed using sodium picosulfate, polyethylene glycol preparations and sodium phosphate in 36.8%, 20.7% and 15.6% of colonoscopy procedures respectively[56].
| Agent | Dosing | Recommendation | Level of evidence |
| PEG | 240 mL every 10 min until rectal output is clear or total of 4 L | Faster, more effective, better-tolerated compared to dietary restriction with cathartics, gut lavage, or mannitol | Grade IA |
| Sulfate-free PEG | 240 mL every 10 min until rectal output is clear or total of 4 L | Better tasting, comparable to PEG in effectiveness and safety, acceptable alternative to PEG | Grade IIB |
| Low-volume PEG/PEG-3350 and bisacodyl | 4 bisacodyl delayed-release tablets at noon, after bowel movement or 6 h, 240 mL every 10 min until 2 L is consumed | Equally effective to standard 4-L PEG, better tolerated, acceptable alternative to 4-L PEG | Grade IA |
| Aqueous sodium phosphate | Two doses of 30 to 45 mL sodium phosphate with 8 oz of liquid 10-12 h apart | Equal alternative to PEG except for pediatric and elderly patients, bowel obstruction, renal failure, congestive heart and liver failure | Grade IA |
| Sodium phosphate tablets | 20 tablets on the evening before the procedure, 12-20 tablets 3-5 h before the procedure | Improved taste and palatability compared to aqueous sodium phosphate, but no improvement in patient tolerance | Grade IA |
Regardless of the type of bowel preparation used, whether it is PEG or sodium phosphate-based, both types appear to have a similar level of bowel cleansing ability. Modifications of these two common types of bowel preparations, such as adding prokinetic agents to PEG[57,58], or adding simethicone to sodium phosphate[59], may provide some improvements in certain instances. However, it is recognized that factors other than the type of bowel cleansing agent used, have an equally, if not more, important role in influencing the quality of bowel preparation in patients undergoing colonoscopy. In general, this can be categorized as either patient-related (i.e., clinical or epidemiological parameters) or procedure-related (e.g., administrative issues relating to bowel preparation or the conduct of colonoscopy) factors. In this review, we will focus on both of these factors and their influence on the quality of bowel preparation among adult patients undergoing colonoscopy.
Several studies have evaluated advancing age as a risk factor for poor bowel preparation in colonoscopy. In a retrospective United States study of 300 patients, univariate analysis demonstrated that a mean age of ≥ 66 years was predictive of poor colonoscopy preparation[60]. In two recent Asian studies, age ≥ 60 years were similarly associated with a poor bowel preparation[27,54]. An increased age is known to be associated with a reduced colonic transit, greater co-morbidity and polypharmacy, all of which are known to impact on colonic cleansing[39,61-64]. However, in a larger prospective study of 649 patients, the age of patients did not appear to have an impact on the quality of bowel preparation in patients undergoing colonoscopy[65]. One possible explanation was that the mean age of patients in this study was 56 years, which is significantly lower than other studies which reported on age as a risk factor for poor bowel preparation.
Studies in both the West[65,66] and the East[67] have demonstrated that male gender is an independent predictor of poor bowel preparation. Among 649 American patients, of whom 21.7% had poor bowel preparation, Ness et al[65] reported that male gender was an independent predictor of poor bowel preparation among other patient-related factors. Chan et al[67] showed that male patients undergoing colonoscopy were 1.6 times more likely to have poor bowel preparation compared to female patients, in a study of 501 Asian patients. Lebwohl further reported that male patients had a 1.4 times risk of poor bowel preparation compared to females in yet another American study of 10 921 patients undergoing colonoscopy[66].
It is well known in most societies that men are less health-conscious compared to women for various reasons[68-70]. Gender differences in reproductive biology, higher morbidity rates in women than in men, differences in health perceptions and the reporting of illnesses, and a greater likelihood that women seek help for prevention of illness[71] are some of the explanations for a lesser healthcare attitude amongst men. It is plausible then that this gender difference may have led to a poorer adherence to bowel preparation instructions among male patients undergoing colonoscopy from both Eastern and Western patients.
Several studies have managed to explore the association between co-morbidities and adequacy of bowel preparation. A recent study of 300 outpatients undergoing colonoscopy identified the “use of more than 8 active prescription medications”, i.e., a surrogate marker for co-morbidity as a predictor for poor bowel preparation[72]. Among the common chronic illnesses known, diabetes has been shown to be consistently associated with poor bowel preparation. In a South Korean study of 367 patients, Chung et al[54] demonstrated that diabetic patients had a 8.6 times risk of poor bowel preparation compared to non-diabetic patients. In yet another study specifically comparing standard PEG bowel preparation between diabetic and non-diabetic patients, Taylor et al[73] demonstrated that an adequate bowel preparation was found in 97% non-diabetic patients compared to 62% of diabetic patients. Diabetes is known to impair colonic and general gastrointestinal transit[74,75], and it is this mechanism that is thought to result in a poorer bowel preparation.
Patients with stroke disease and dementia have additionally been demonstrated to have a higher risk of poor bowel preparation[65], potentially as a result of an altered gastrointestinal motility as well and their inability to comply with bowel preparation instructions. A single study has additionally identified prior gastrointestinal and pelvic surgery as risk factor for inadequate bowel preparation[54].
The setting in which patients are referred for a colonoscopy, i.e., either from an in-patient or out-patient setting, is yet another surrogate marker for the impact of co-morbidity on level of colon cleanliness. Inpatient status has been associated with poorer bowel preparation in several studies[65,67,76], and this has been attributed to prolonged immobility and poor tolerance to purgatives due to co-morbid illness. Even in colonic surgery, an out-patient bowel preparation, as opposed to an in-patient preparation, has been shown to result in a better clinical outcome due increased co-morbidity in the latter[77].
Bowel preparation regimens need to be adhered to ensure a good quality of preparation during colonoscopy (see later). As standard bowel preparation usually requires a combination of dietary restrictions and several steps of purgative administration, a clear understanding of the process and strict adherence to instructions (usually in a written format) is vital. A poor understanding of this process, and its’ importance, has been shown to be more prevalent among patients from a lower socioeconomic background. A recent United States-based study identified poor bowel preparation to be more common among patients who needed English-language interpretation (for bowel preparation instructions) and those on Medicaid insurance (a marker of low socioeconomic status)[72]. A lower education level, as a marker of lower socioeconomic status, was recently shown to be an independent predictor of poor bowel preparation in an Asian study of 501 outpatients[67]. In contrast, enhanced education and specific counseling of adult patients on bowel preparation instructions was shown to improve the quality of bowel preparation in an elegant Canadian study of 38 patients[76].
As mentioned before, a standard bowel preparation usually involves several steps. Regardless of the type of purgative used, non-adherence to these steps alone have been shown to be an important determinant of quality of bowel preparation. Among several other factors which predicted poor bowel preparation, Ness et al[65] had identified that a failure to adequately follow preparation instructions was associated with a 2.68 odds ratio for predicting poor bowel preparation. In a recent American study of 300 patients who underwent screening colonoscopy for cancer, Nguyen et al[72] reported that 86.7% of patients with a poor/inadequate bowel preparation had failed to either complete the bowel preparation or follow written instructions. These findings were similarly reported in a Malaysian study of 501 patients, whereby non-adherence to purgative instructions was associated with a 4.76 risk of poor bowel preparation[67]. Whilst non-adherence to preparation instructions is an obvious determinant of the quality of bowel preparation, it is generally unreliable as it depends on self-reporting by patients. It is well recognized that many patients are reticent to admit non-adherence or they may not even recognize non-compliance themselves[65]. Nevertheless, it is important to identify factors contributing to non-adherence of instructions as this provides an opportunity to intervene and enhance quality. A lower socioeconomic status has been identified as one of the main reasons for non-adherence to bowel preparation instructions[72] and it is likely that male gender may be a contributing factor[66,67], for reasons outlined previously.
Several studies have examined the effect of timing of bowel purgative administration (mostly PEG) and its’ impact on quality of bowel preparation. In a large study of 317 patients undergoing an afternoon colonoscopy, Church et al demonstrated that a “same-day” administration resulted in a significantly better quality of bowel preparation compared to a “one day before” timing, using the same quantity of PEG solution[78]. Regardless of the location of the colon, patients with a “same day” bowel preparation had a greater proportion of “excellent grade” cleanliness and a lower proportion of “fair grade” cleanliness compared to patients who had consumed purgatives the day before[78]. Two other studies examining “day before”vs“same day” preparations have managed to demonstrate a similar superior efficacy of the “same day” preparations[79,80], with an Italian study even suggesting that this timing improved the detection rates of colonic adenomas[80]. A prolonged duration between purgative administration and timing of colonoscopy is thought to result in proximal colon contamination from the small bowel and hence a poorer colon cleansing ability. In a different study, El Sayed et al[81] investigated the effect of a split-dose administration of PEG, whereby 187 patients were randomised to either “3 L PEG + dietary restriction one day before”vs“2 L PEG + Bisacodyl one day before + 1 L PEG on the same day” of the colonoscopy procedure. Although a little more complicated, the authors were able to demonstrate that the split-dose regime was better tolerated and resulted in better colon cleansing.
The time from booking a routine colonoscopy procedure to the actual appointment date, i.e., the appointment waiting time, may influence the quality of bowel preparation due to individual patient’s ability to recall bowel preparation instructions. To date, a single study among Malaysian patients in a public institution has demonstrated that a prolonged appointment waiting time of > 16 wk was associated with a 1.86 risk of poor bowel preparation[67]. A previous retrospective study in the United States did not identify appointment waiting times as a risk factor for poor bowel preparation, but the mean waiting time was only 4.39 wk in this study[72]. Whilst most endoscopy units strive to shorten their outpatient waiting times for appointments for index colonoscopies, the increasing demand from colorectal cancer screening together with limited resources in most healthcare systems requires urgent attention.
Preferences for either PEG or phosphate-based purgative preparations may differ between populations. Nevertheless, it is apparent that patient-related or procedure-related factors, summarized in Table 2, have a significant influence on the quality of bowel preparation among adults undergoing colonoscopy. Although not all factors can be necessarily addressed, modifying the standard bowel preparation regime for such patients may enhance the quality of bowel preparation, reducing the negative impact of poor bowel preparation on individuals and colonoscopy services as a whole.
| Patient-related factors | Procedure-related factors |
| Age > 65 yr | |
| Male gender | Adherence to bowel preparation instructions |
| Co-morbidity | Timing of purgative administration |
| Diabetes | |
| Stroke disease | |
| Inpatient status | |
| Low socioeconomic status | Appointment waiting times |
P- Reviewers Gu J, Yoshida N S- Editor Song XX L- Editor A E- Editor Zhang DN
| 1. | Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D. Global cancer statistics. CA Cancer J Clin. 2011;61:69-90. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 23762] [Cited by in F6Publishing: 25175] [Article Influence: 1936.5] [Reference Citation Analysis (3)] |
| 2. | Sung JJ, Lau JY, Young GP, Sano Y, Chiu HM, Byeon JS, Yeoh KG, Goh KL, Sollano J, Rerknimitr R. Asia Pacific consensus recommendations for colorectal cancer screening. Gut. 2008;57:1166-1176. [PubMed] [Cited in This Article: ] |
| 3. | Yiu HY, Whittemore AS, Shibata A. Increasing colorectal cancer incidence rates in Japan. Int J Cancer. 2004;109:777-781. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 87] [Cited by in F6Publishing: 96] [Article Influence: 4.8] [Reference Citation Analysis (0)] |
| 4. | Ji BT, Devesa SS, Chow WH, Jin F, Gao YT. Colorectal cancer incidence trends by subsite in urban Shanghai, 1972-1994. Cancer Epidemiol Biomarkers Prev. 1998;7:661-666. [PubMed] [Cited in This Article: ] |
| 5. | You W, Jin F, Gridley G, Schatzkin A, Yang G, Rosenberg P, Xiang Y, Hu Y, Li Q. Trends in colorectal cancer rates in urban shanghai, 1972-1996, in relation to dietary changes. Ann Epidemiol. 2000;10:469. [PubMed] [Cited in This Article: ] |
| 6. | Perea J, Alvaro E, Rodríguez Y, Gravalos C, Sánchez-Tomé E, Rivera B, Colina F, Carbonell P, González-Sarmiento R, Hidalgo M. Approach to early-onset colorectal cancer: clinicopathological, familial, molecular and immunohistochemical characteristics. World J Gastroenterol. 2010;16:3697-3703. [PubMed] [Cited in This Article: ] |
| 7. | Kahi CJ, Rex DK. Screening and surveillance of colorectal cancer. Gastrointest Endosc Clin N Am. 2005;15:533-47, ix. [PubMed] [Cited in This Article: ] |
| 8. | Lieberman D. Screening, surveillance, and prevention of colorectal cancer. Gastrointest Endosc Clin N Am. 2008;18:595-605, xi. [PubMed] [Cited in This Article: ] |
| 9. | McLoughlin RM, O’Morain CA. Colorectal cancer screening. World J Gastroenterol. 2006;12:6747-6750. [PubMed] [Cited in This Article: ] |
| 10. | Davila RE, Rajan E, Baron TH, Adler DG, Egan JV, Faigel DO, Gan SI, Hirota WK, Leighton JA, Lichtenstein D. ASGE guideline: colorectal cancer screening and surveillance. Gastrointest Endosc. 2006;63:546-557. [PubMed] [Cited in This Article: ] |
| 11. | Schoen RE, Pinsky PF, Weissfeld JL, Yokochi LA, Church T, Laiyemo AO, Bresalier R, Andriole GL, Buys SS, Crawford ED. Colorectal-cancer incidence and mortality with screening flexible sigmoidoscopy. N Engl J Med. 2012;366:2345-2357. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 672] [Cited by in F6Publishing: 697] [Article Influence: 58.1] [Reference Citation Analysis (1)] |
| 12. | Rosa I, Fidalgo P, Soares J, Vinga S, Oliveira C, Silva JP, Ferro SM, Chaves P, Oliveira AG, Leitão CN. Adenoma incidence decreases under the effect of polypectomy. World J Gastroenterol. 2012;18:1243-1248. [PubMed] [DOI] [Cited in This Article: ] [Cited by in CrossRef: 5] [Cited by in F6Publishing: 6] [Article Influence: 0.5] [Reference Citation Analysis (0)] |
| 13. | Zheng S, Liu XY, Ding KF, Wang LB, Qiu PL, Ding XF, Shen YZ, Shen GF, Sun QR, Li WD. Reduction of the incidence and mortality of rectal cancer by polypectomy: a prospective cohort study in Haining County. World J Gastroenterol. 2002;8:488-492. [PubMed] [Cited in This Article: ] |
| 14. | Lieberman DA, Weiss DG, Bond JH, Ahnen DJ, Garewal H, Chejfec G. Use of colonoscopy to screen asymptomatic adults for colorectal cancer. Veterans Affairs Cooperative Study Group 380. N Engl J Med. 2000;343:162-168. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 1214] [Cited by in F6Publishing: 1180] [Article Influence: 49.2] [Reference Citation Analysis (0)] |
| 15. | Emura F, Saito Y, Ikematsu H. Narrow-band imaging optical chromocolonoscopy: advantages and limitations. World J Gastroenterol. 2008;14:4867-4872. [PubMed] [Cited in This Article: ] |
| 16. | Singh R, Owen V, Shonde A, Kaye P, Hawkey C, Ragunath K. White light endoscopy, narrow band imaging and chromoendoscopy with magnification in diagnosing colorectal neoplasia. World J Gastrointest Endosc. 2009;1:45-50. [PubMed] [DOI] [Cited in This Article: ] [Cited by in CrossRef: 20] [Cited by in F6Publishing: 16] [Article Influence: 1.1] [Reference Citation Analysis (0)] |
| 17. | Rex DK, Kahi C, O’Brien M, Levin TR, Pohl H, Rastogi A, Burgart L, Imperiale T, Ladabaum U, Cohen J. The American Society for Gastrointestinal Endoscopy PIVI (Preservation and Incorporation of Valuable Endoscopic Innovations) on real-time endoscopic assessment of the histology of diminutive colorectal polyps. Gastrointest Endosc. 2011;73:419-422. [PubMed] [Cited in This Article: ] |
| 18. | Puli SR, Kakugawa Y, Gotoda T, Antillon D, Saito Y, Antillon MR. Meta-analysis and systematic review of colorectal endoscopic mucosal resection. World J Gastroenterol. 2009;15:4273-4277. [PubMed] [Cited in This Article: ] |
| 19. | Mahadeva S, Rembacken BJ. Standard “inject and cut” endoscopic mucosal resection technique is practical and effective in the management of superficial colorectal neoplasms. Surg Endosc. 2009;23:417-422. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 25] [Cited by in F6Publishing: 26] [Article Influence: 1.6] [Reference Citation Analysis (0)] |
| 20. | Lhewa DY, Strate LL. Pros and cons of colonoscopy in management of acute lower gastrointestinal bleeding. World J Gastroenterol. 2012;18:1185-1190. [PubMed] [DOI] [Cited in This Article: ] [Cited by in CrossRef: 64] [Cited by in F6Publishing: 54] [Article Influence: 4.5] [Reference Citation Analysis (0)] |
| 21. | Feo L, Schaffzin DM. Colonic stents: the modern treatment of colonic obstruction. Adv Ther. 2011;28:73-86. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 28] [Cited by in F6Publishing: 33] [Article Influence: 2.5] [Reference Citation Analysis (0)] |
| 22. | Kaltenbach T, Watson R, Shah J, Friedland S, Sato T, Shergill A, McQuaid K, Soetikno R. Colonoscopy with clipping is useful in the diagnosis and treatment of diverticular bleeding. Clin Gastroenterol Hepatol. 2012;10:131-137. [PubMed] [Cited in This Article: ] |
| 23. | Suzuki N, Saunders BP, Thomas-Gibson S, Akle C, Marshall M, Halligan S. Colorectal stenting for malignant and benign disease: outcomes in colorectal stenting. Dis Colon Rectum. 2004;47:1201-1207. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 110] [Cited by in F6Publishing: 116] [Article Influence: 5.8] [Reference Citation Analysis (0)] |
| 24. | Adler A, Wegscheider K, Lieberman D, Aminalai A, Aschenbeck J, Drossel R, Mayr M, Mroß M, Scheel M, Schröder A. Factors determining the quality of screening colonoscopy: a prospective study on adenoma detection rates, from 12 134 examinations (Berlin colonoscopy project 3, BECOP-3). Gut. 2013;62:236-241. [PubMed] [Cited in This Article: ] |
| 25. | Lebwohl B, Kastrinos F, Glick M, Rosenbaum AJ, Wang T, Neugut AI. The impact of suboptimal bowel preparation on adenoma miss rates and the factors associated with early repeat colonoscopy. Gastrointest Endosc. 2011;73:1207-1214. [PubMed] [Cited in This Article: ] |
| 26. | Harewood GC, Sharma VK, de Garmo P. Impact of colonoscopy preparation quality on detection of suspected colonic neoplasia. Gastrointest Endosc. 2003;58:76-79. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 524] [Cited by in F6Publishing: 573] [Article Influence: 27.3] [Reference Citation Analysis (0)] |
| 27. | Chan WK, Saravanan A, Manikam J, Goh KL, Mahadeva S. Appointment waiting times and education level influence the quality of bowel preparation in adult patients undergoing colonoscopy. BMC Gastroenterol. 2011;11:86. [PubMed] [Cited in This Article: ] |
| 28. | Froehlich F, Wietlisbach V, Gonvers JJ, Burnand B, Vader JP. Impact of colonic cleansing on quality and diagnostic yield of colonoscopy: the European Panel of Appropriateness of Gastrointestinal Endoscopy European multicenter study. Gastrointest Endosc. 2005;61:378-384. [PubMed] [Cited in This Article: ] |
| 29. | Hendry PO, Jenkins JT, Diament RH. The impact of poor bowel preparation on colonoscopy: a prospective single centre study of 10,571 colonoscopies. Colorectal Dis. 2007;9:745-748. [PubMed] [Cited in This Article: ] |
| 30. | Aslinia F, Uradomo L, Steele A, Greenwald BD, Raufman JP. Quality assessment of colonoscopic cecal intubation: an analysis of 6 years of continuous practice at a university hospital. Am J Gastroenterol. 2006;101:721-731. [PubMed] [Cited in This Article: ] |
| 31. | Burke CA, Church JM. Enhancing the quality of colonoscopy: the importance of bowel purgatives. Gastrointest Endosc. 2007;66:565-573. [PubMed] [Cited in This Article: ] |
| 32. | Aronchick CA, Lipshutz WH, Wright SH, Dufrayne F, Bergman G. A novel tableted purgative for colonoscopic preparation: efficacy and safety comparisons with Colyte and Fleet Phospho-Soda. Gastrointest Endosc. 2000;52:346-352. [PubMed] [Cited in This Article: ] |
| 33. | Rostom A, Jolicoeur E. Validation of a new scale for the assessment of bowel preparation quality. Gastrointest Endosc. 2004;59:482-486. [PubMed] [Cited in This Article: ] |
| 34. | Rostom A, Jolicoeur E, Dubé C, Grégoire S, Patel D, Saloojee N, Lowe C. A randomized prospective trial comparing different regimens of oral sodium phosphate and polyethylene glycol-based lavage solution in the preparation of patients for colonoscopy. Gastrointest Endosc. 2006;64:544-552. [PubMed] [Cited in This Article: ] |
| 35. | Bitoun A, Ponchon T, Barthet M, Coffin B, Dugué C, Halphen M. Results of a prospective randomised multicentre controlled trial comparing a new 2-L ascorbic acid plus polyethylene glycol and electrolyte solution vs. sodium phosphate solution in patients undergoing elective colonoscopy. Aliment Pharmacol Ther. 2006;24:1631-1642. [PubMed] [Cited in This Article: ] |
| 36. | Allaire J, Thompson WO, Cash BD, Galt DJ. A quality improvement project comparing two regimens of medication for colonoscopy preparation. Gastroenterol Nurs. 2004;27:3-8. [PubMed] [Cited in This Article: ] |
| 37. | Huppertz-Hauss G, Bretthauer M, Sauar J, Paulsen J, Kjellevold Ø, Majak B, Hoff G. Polyethylene glycol versus sodium phosphate in bowel cleansing for colonoscopy: a randomized trial. Endoscopy. 2005;37:537-541. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 47] [Cited by in F6Publishing: 50] [Article Influence: 2.6] [Reference Citation Analysis (0)] |
| 38. | Hwang KL, Chen WT, Hsiao KH, Chen HC, Huang TM, Chiu CM, Hsu GH. Prospective randomized comparison of oral sodium phosphate and polyethylene glycol lavage for colonoscopy preparation. World J Gastroenterol. 2005;11:7486-7493. [PubMed] [Cited in This Article: ] |
| 39. | Schiller LR. Clinical pharmacology and use of laxatives and lavage solutions. J Clin Gastroenterol. 1999;28:11-18. [PubMed] [Cited in This Article: ] |
| 40. | 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; discussion 233-4. [PubMed] [Cited in This Article: ] |
| 41. | DiPalma JA, Wolff BG, Meagher A, Cleveland Mv. Comparison of reduced volume versus four liters sulfate-free electrolyte lavage solutions for colonoscopy colon cleansing. Am J Gastroenterol. 2003;98:2187-2191. [PubMed] [Cited in This Article: ] |
| 42. | Ker TS. Comparison of reduced volume versus four-liter electrolyte lavage solutions for colon cleansing. Am Surg. 2006;72:909-911. [PubMed] [Cited in This Article: ] |
| 43. | Sharma VK, Chockalingham SK, Ugheoke EA, Kapur A, Ling PH, Vasudeva R, Howden CW. Prospective, randomized, controlled comparison of the use of polyethylene glycol electrolyte lavage solution in four-liter versus two-liter volumes and pretreatment with either magnesium citrate or bisacodyl for colonoscopy preparation. Gastrointest Endosc. 1998;47:167-171. [PubMed] [Cited in This Article: ] |
| 44. | Juluri R, Eckert G, Imperiale TF. Meta-analysis: randomized controlled trials of 4-L polyethylene glycol and sodium phosphate solution as bowel preparation for colonoscopy. Aliment Pharmacol Ther. 2010;32:171-181. [PubMed] [Cited in This Article: ] |
| 45. | Juluri R, Eckert G, Imperiale TF. Polyethylene glycol vs. sodium phosphate for bowel preparation: a treatment arm meta-analysis of randomized controlled trials. BMC Gastroenterol. 2011;11:38. [PubMed] [Cited in This Article: ] |
| 46. | Kolts BE, Lyles WE, Achem SR, Burton L, Geller AJ, MacMath T. A comparison of the effectiveness and patient tolerance of oral sodium phosphate, castor oil, and standard electrolyte lavage for colonoscopy or sigmoidoscopy preparation. Am J Gastroenterol. 1993;88:1218-1223. [PubMed] [Cited in This Article: ] |
| 47. | Rex DK, Schwartz H, Goldstein M, Popp J, Katz S, Barish C, Karlstadt RG, Rose M, Walker K, Lottes S. Safety and colon-cleansing efficacy of a new residue-free formulation of sodium phosphate tablets. Am J Gastroenterol. 2006;101:2594-2604. [PubMed] [Cited in This Article: ] |
| 48. | Kastenberg D, Chasen R, Choudhary C, Riff D, Steinberg S, Weiss E, Wruble L. Efficacy and safety of sodium phosphate tablets compared with PEG solution in colon cleansing: two identically designed, randomized, controlled, parallel group, multicenter phase III trials. Gastrointest Endosc. 2001;54:705-713. [PubMed] [Cited in This Article: ] |
| 49. | Wruble L, Demicco M, Medoff J, Safdi A, Bernstein J, Dalke D, Rose M, Karlstadt RG, Ettinger N, Zhang B. Residue-free sodium phosphate tablets (OsmoPrep) versus Visicol for colon cleansing: a randomized, investigator-blinded trial. Gastrointest Endosc. 2007;65:660-670. [PubMed] [Cited in This Article: ] |
| 50. | Wexner SD, Beck DE, Baron TH, Fanelli RD, Hyman N, Shen B, Wasco KE. A consensus document on bowel preparation before colonoscopy: prepared by a Task Force from the American Society of Colon and Rectal Surgeons (ASCRS), the American Society for Gastrointestinal Endoscopy (ASGE), and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). Surg Endosc. 2006;20:1161. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 34] [Cited by in F6Publishing: 31] [Article Influence: 1.7] [Reference Citation Analysis (0)] |
| 51. | Clark LE, Dipalma JA. Safety issues regarding colonic cleansing for diagnostic and surgical procedures. Drug Saf. 2004;27:1235-1242. [PubMed] [Cited in This Article: ] |
| 52. | Woo YM, Crail S, Curry G, Geddes CC. A life threatening complication after ingestion of sodium phosphate bowel preparation. BMJ. 2006;333:589-590. [PubMed] [Cited in This Article: ] |
| 53. | Spada C, Hassan C, Galmiche JP, Neuhaus H, Dumonceau JM, Adler S, Epstein O, Gay G, Pennazio M, Rex DK. Colon capsule endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy. 2012;44:527-536. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 167] [Cited by in F6Publishing: 178] [Article Influence: 14.8] [Reference Citation Analysis (0)] |
| 54. | Chung YW, Han DS, Park KH, Kim KO, Park CH, Hahn T, Yoo KS, Park SH, Kim JH, Park CK. Patient factors predictive of inadequate bowel preparation using polyethylene glycol: a prospective study in Korea. J Clin Gastroenterol. 2009;43:448-452. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 129] [Cited by in F6Publishing: 111] [Article Influence: 7.4] [Reference Citation Analysis (0)] |
| 55. | Barkun A, Chiba N, Enns R, Marcon M, Natsheh S, Pham C, Sadowski D, Vanner S. Commonly used preparations for colonoscopy: efficacy, tolerability, and safety--a Canadian Association of Gastroenterology position paper. Can J Gastroenterol. 2006;20:699-710. [PubMed] [Cited in This Article: ] |
| 56. | Bowles CJ, Leicester R, Romaya C, Swarbrick E, Williams CB, Epstein O. A prospective study of colonoscopy practice in the UK today: are we adequately prepared for national colorectal cancer screening tomorrow? Gut. 2004;53:277-283. [PubMed] [Cited in This Article: ] |
| 57. | Tajika M, Niwa Y, Bhatia V, Kawai H, Kondo S, Sawaki A, Mizuno N, Hara K, Hijioka S, Matsumoto K. Efficacy of mosapride citrate with polyethylene glycol solution for colonoscopy preparation. World J Gastroenterol. 2012;18:2517-2525. [PubMed] [DOI] [Cited in This Article: ] [Cited by in CrossRef: 25] [Cited by in F6Publishing: 31] [Article Influence: 2.6] [Reference Citation Analysis (0)] |
| 58. | Grigg E, Schubert MC, Hall J, Rahhal F, Raina D, Sridhar S, Chamberlain SM. Lubiprostone used with polyethylene glycol in diabetic patients enhances colonoscopy preparation quality. World J Gastrointest Endosc. 2010;2:263-267. [PubMed] [DOI] [Cited in This Article: ] [Cited by in CrossRef: 10] [Cited by in F6Publishing: 10] [Article Influence: 0.7] [Reference Citation Analysis (0)] |
| 59. | Tongprasert S, Sobhonslidsuk A, Rattanasiri S. Improving quality of colonoscopy by adding simethicone to sodium phosphate bowel preparation. World J Gastroenterol. 2009;15:3032-3037. [PubMed] [Cited in This Article: ] |
| 60. | Nguyen DL, Wieland M. Risk factors predictive of poor quality preparation during average risk colonoscopy screening: the importance of health literacy. J Gastrointestin Liver Dis. 2010;19:369-372. [PubMed] [Cited in This Article: ] |
| 61. | Gallagher P, O’Mahony D. Constipation in old age. Best Pract Res Clin Gastroenterol. 2009;23:875-887. [PubMed] [Cited in This Article: ] |
| 62. | Heppner HJ, Christ M, Gosch M, Mühlberg W, Bahrmann P, Bertsch T, Sieber C, Singler K. Polypharmacy in the elderly from the clinical toxicologist perspective. Z Gerontol Geriatr. 2012;45:473-478. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 15] [Cited by in F6Publishing: 16] [Article Influence: 1.5] [Reference Citation Analysis (0)] |
| 63. | Cameron AJ, Shaw JE, Zimmet PZ. The metabolic syndrome: prevalence in worldwide populations. Endocrinol Metab Clin North Am. 2004;33:351-75, table of contents. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 602] [Cited by in F6Publishing: 581] [Article Influence: 29.1] [Reference Citation Analysis (0)] |
| 64. | Roger VL, Go AS, Lloyd-Jones DM, Benjamin EJ, Berry JD, Borden WB, Bravata DM, Dai S, Ford ES, Fox CS. Heart disease and stroke statistics--2012 update: a report from the American Heart Association. Circulation. 2012;125:e2-e220. [PubMed] [Cited in This Article: ] |
| 65. | Ness RM, Manam R, Hoen H, Chalasani N. Predictors of inadequate bowel preparation for colonoscopy. Am J Gastroenterol. 2001;96:1797-1802. [PubMed] [Cited in This Article: ] |
| 66. | Lebwohl B, Wang TC, Neugut AI. Socioeconomic and other predictors of colonoscopy preparation quality. Dig Dis Sci. 2010;55:2014-2020. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 116] [Cited by in F6Publishing: 89] [Article Influence: 6.4] [Reference Citation Analysis (0)] |
| 67. | Chan WK, Saravanan A, Manikam J, Goh KL, Mahadeva S. Appointment waiting times and education level influence the quality of bowel preparation in adult patients undergoing colonoscopy. BMC Gastroenterol. 2011;11:86. [PubMed] [Cited in This Article: ] |
| 68. | Hibbard JH, Pope CR. Gender roles, illness orientation and use of medical services. Soc Sci Med. 1983;17:129-137. [PubMed] [Cited in This Article: ] |
| 69. | Hibbard JH, Pope CR. Another look at sex differences in the use of medical care: illness orientation and the types of morbidities for which services are used. Women Health. 1986;11:21-36. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 70] [Cited by in F6Publishing: 72] [Article Influence: 1.9] [Reference Citation Analysis (0)] |
| 70. | Green CA, Pope CR. Gender, psychosocial factors and the use of medical services: a longitudinal analysis. Soc Sci Med. 1999;48:1363-1372. [PubMed] [Cited in This Article: ] |
| 71. | Bertakis KD, Azari R, Helms LJ, Callahan EJ, Robbins JA. Gender differences in the utilization of health care services. J Fam Pract. 2000;49:147-152. [PubMed] [Cited in This Article: ] |
| 72. | Nguyen DL, Wieland M. Risk factors predictive of poor quality preparation during average risk colonoscopy screening: the importance of health literacy. J Gastrointestin Liver Dis. 2010;19:369-372. [PubMed] [Cited in This Article: ] |
| 73. | Taylor C, Schubert ML. Decreased efficacy of polyethylene glycol lavage solution (golytely) in the preparation of diabetic patients for outpatient colonoscopy: a prospective and blinded study. Am J Gastroenterol. 2001;96:710-714. [PubMed] [Cited in This Article: ] |
| 74. | Battle WM, Snape WJ, Alavi A, Cohen S, Braunstein S. Colonic dysfunction in diabetes mellitus. Gastroenterology. 1980;79:1217-1221. [PubMed] [Cited in This Article: ] |
| 75. | Chandrasekharan B, Anitha M, Blatt R, Shahnavaz N, Kooby D, Staley C, Mwangi S, Jones DP, Sitaraman SV, Srinivasan S. Colonic motor dysfunction in human diabetes is associated with enteric neuronal loss and increased oxidative stress. Neurogastroenterol Motil. 2011;23:131-18, e26. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 103] [Cited by in F6Publishing: 120] [Article Influence: 9.2] [Reference Citation Analysis (0)] |
| 76. | Rosenfeld G, Krygier D, Enns RA, Singham J, Wiesinger H, Bressler B. The impact of patient education on the quality of inpatient bowel preparation for colonoscopy. Can J Gastroenterol. 2010;24:543-546. [PubMed] [Cited in This Article: ] |
| 77. | Lee EC, Roberts PL, Taranto R, Schoetz DJ, Murray JJ, Coller JA. Inpatient vs. outpatient bowel preparation for elective colorectal surgery. Dis Colon Rectum. 1996;39:369-373. [PubMed] [Cited in This Article: ] |
| 78. | Church JM. Effectiveness of polyethylene glycol antegrade gut lavage bowel preparation for colonoscopy--timing is the key! Dis Colon Rectum. 1998;41:1223-1225. [PubMed] [Cited in This Article: ] |
| 79. | Gupta T, Mandot A, Desai D, Abraham P, Joshi A, Shah S. Comparison of two schedules (previous evening versus same morning) of bowel preparation for colonoscopy. Endoscopy. 2007;39:706-709. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 40] [Cited by in F6Publishing: 42] [Article Influence: 2.5] [Reference Citation Analysis (0)] |
| 80. | Parra-Blanco A, Nicolas-Perez D, Gimeno-Garcia A, Grosso B, Jimenez A, Ortega J, Quintero E. The timing of bowel preparation before colonoscopy determines the quality of cleansing, and is a significant factor contributing to the detection of flat lesions: a randomized study. World J Gastroenterol. 2006;12:6161-6166. [PubMed] [Cited in This Article: ] |
| 81. | El Sayed AM, Kanafani ZA, Mourad FH, Soweid AM, Barada KA, Adorian CS, Nasreddine WA, Sharara AI. A randomized single-blind trial of whole versus split-dose polyethylene glycol-electrolyte solution for colonoscopy preparation. Gastrointest Endosc. 2003;58:36-40. [PubMed] [DOI] [Cited in This Article: ] [Cited by in Crossref: 130] [Cited by in F6Publishing: 142] [Article Influence: 6.8] [Reference Citation Analysis (0)] |