Current recommendations for colonoscopy preparation emphasize a patient-centered approach designed to improve bowel cleanliness, reduce discomfort, and promote adherence to preparation regimens. Key international medical societies, including the American College of Gastroenterology (ACG) and the European Society of Gastrointestinal Endoscopy (ESGE), updated colonoscopy preparation guidelines in 2024 and 2025, with the broader goal of improving adenoma detection rates and procedural quality indicators. These updates integrate evidence-based practices to refine dosing strategies, patient education, and individualized regimens for high-risk populations, such as individuals with inflammatory bowel disease or chronic kidney disease (1).
Current recommendations for colonoscopy preparation reiterate the superiority of the split-dose regimen, which involves taking two doses of polyethylene glycol (PEG)-based solutions, with the second dose taken four to six hours before the colonoscopy. This approach yields higher-quality bowel cleansing and greater patient satisfaction than single-dose evening regimens. The split-dose method, supported by a long history of clinical data, remains the gold standard due to its ability to maintain mucosal visibility and minimize residue in the colon (2). Low-volume PEG formulations (2L PEG plus ascorbic acid) have emerged as effective, well-tolerated alternatives to traditional 4L PEG solutions. However, the choice of regimen should be guided by patient comorbidities, particularly renal or cardiac dysfunction.
When ESGE guidelines were updated in 2024, a key change was the emphasis on dietary flexibility in colonoscopy preparation. Although the traditional clear-liquid diet the day before colonoscopy has been standard, new evidence supports a low-residue diet (LRD) two days prior, followed by clear liquids the day before the procedure. An LRD permits small portions of low-fiber foods, such as white bread, lean meats, eggs, and dairy, while excluding fruits, vegetables, and whole grains, which leave fibrous residue in the colon. This shift toward the LRD is based on studies demonstrating that it maintains the quality of bowel preparation while significantly improving patient comfort and adherence (3). Patients who follow the LRD report reduced hunger, fewer pre-procedure cancellations, and a greater willingness to repeat the preparation if needed.
Patient education has become a key factor in preparation success. A 2025 evidence map by Li et al. showed that structured education, delivered verbally, in writing, or digitally, significantly improves bowel cleanliness scores and reduces procedure cancellations (4). Educational interventions that allow for self-assessment and provide tailored reminders have been shown to increase adequate bowel preparation rates by up to 20%.
Emerging research also supports integrating digital tools and quality improvement initiatives that continuously monitor preparation adequacy, adenoma detection rates, and compliance with updated metrics. At certain facilities since 2024, continuous quality integration projects have linked these indicators directly to endoscopy units’ performance metrics, encouraging standardization and accountability across centers (5).
Updated guidelines for colonoscopy preparation advocate personalized, evidence-based strategies that prioritize split-dose PEG regimens and expanded dietary options, such as the low-residue diet. They also emphasize comprehensive patient education. These refinements aim to improve procedural quality, reduce variability in bowel preparation outcomes, and ultimately enhance the detection of neoplastic lesions. As digital monitoring and patient engagement tools evolve, adherence to these modernized guidelines is expected to optimize colorectal cancer screening outcomes globally.
References
1. Kay CL, Bader GA, Miller CB. Traditional and Novel Colonoscopy Quality Metrics: What’s Important in 2025. Curr Gastroenterol Rep. 2025;27(1):58. Published 2025 Aug 8. doi:10.1007/s11894-025-01006-1
2. Ferlitsch M, Hassan C, Bisschops R, et al. Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2024. Endoscopy. 2024;56(7):516-545. doi:10.1055/a-2304-3219
3. Kapoor C, Zhang S, Ramalingam N, Liverant M, Ku L, Hassid B. S402 Keeping You Full and Clear: Low Residue Diet Prior to Colonoscopy. Am J Gastroenterol. 2024;119(10 Suppl):S285–S286. doi:10.14309/01.ajg.0001030976.95076.cf
4. Li N, Ye M, Wu Q, Li B, Wang Y, Li W. Clinical outcomes of bowel preparation education strategies in colonoscopy: An evidence map of systematic reviews. Medicine (Baltimore). 2025;104(39):e44644. doi:10.1097/MD.0000000000044644
5. Rex DK. Colonoscopy Remains an Important Option for Primary Screening for Colorectal Cancer. Dig Dis Sci. 2025;70(5):1595-1605. doi:10.1007/s10620-024-08760-8