Updated Colonoscopy Guidelines Emphasize Split-Dose Regimen, Quality Tracking
A new update published in The American Journal of Gastroenterology from the US Multi-Society Task Force on Colorectal Cancer revises and refines recommendations for optimizing bowel preparation in colonoscopy.
The recommendations—developed by the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy—aim to support consistent, high-quality screening and surveillance by improving bowel cleansing protocols.
Central to the updated guidance is the strong recommendation for the use of split-dose bowel preparation regimens, which according to the the Task Force enhance the cleanliness of the colon and improve overall procedure quality. The split-dose method involves taking half the preparation the evening before and the remaining half the morning of the colonoscopy. This technique has been shown to be superior in terms of colon cleanliness and adenoma detection rates compared to single-dose methods.
For patients undergoing afternoon colonoscopies, same-day regimens are considered an acceptable alternative. However, the guidance advises, “We suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy.”
In addition to dosing strategies, the Task Force recommends limiting dietary restrictions to the day before the colonoscopy, allowing for improved patient compliance without compromising preparation quality. Both clear liquid diets and low-residue diets are acceptable. Adjunctive use of oral simethicone is also encouraged, which may help reduce bubbles and improve mucosal visualization.
Importantly, the guidelines introduce a performance metric for bowel preparation adequacy. “Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended,” with a goal of greater than 90% adequacy rate. This benchmark underscores the central role of bowel prep quality in maintaining high procedural standards, including adenoma detection and cecal intubation rates.
While the consensus statements primarily apply to average-risk individuals, the document includes tailored recommendations for those at increased risk of inadequate preparation, ensuring a more individualized approach to patient care.
Overall, the updated guidelines stress that adequate bowel preparation is not just a procedural formality—it is a critical determinant of colonoscopy quality. By reinforcing evidence-based regimens and encouraging systematic tracking, the Task Force seeks to reduce variability in practice and enhance outcomes in colorectal cancer prevention.
Reference
Jacobson BC, Anderson JC, Burke CA, et al. Optimizing bowel preparation quality for colonoscopy: consensus recommendations by the US multi-society task force on colorectal cancer. Am J Gastroenterol. Published online March 4, 2025. DOI: 10.14309/ajg.0000000000003287
