Colonoscopy Preparation Guidelines

General Preparation Recommendations

A split-dose bowel preparation regimen is strongly recommended for all patients, regardless of whether high-volume or low-volume preparation is used, according to the American Gastroenterological Association 1
The American Gastroenterological Association suggests 2-liter bowel preparation regimens over 4-liter regimens due to better patient tolerance while maintaining adequate cleansing 1
Selection of bowel preparation should consider the individual's medical history, medications, and prior colonoscopy preparation adequacy, as recommended by the American Gastroenterological Association 1
Hyperosmotic regimens should be avoided in individuals at risk for volume overload or electrolyte disturbances, according to the American Gastroenterological Association 1
Oral simethicone can be used as an adjunctive agent for bowel preparation, as suggested by the American Gastroenterological Association 1

The American Gastroenterological Association strongly recommends split-dose administration for all colonoscopies 1
The second portion of the split-dose regimen should begin 4-6 hours before colonoscopy and be completed at least 2 hours before the procedure, as recommended by the American Gastroenterological Association 1, 2
Each additional hour between the last purgative ingestion and colonoscopy can decrease the likelihood of good preparation by up to 10%, according to the American Gastroenterological Association 2

The American Gastroenterological Association recommends following a low-residue/low-fiber diet for early and midday meals on the day before colonoscopy, although this citation is from Praxis Medical Insights, an alternative source is not provided 4

Both verbal and written patient education instructions should be provided for all components of the colonoscopy preparation, as recommended by the American Gastroenterological Association 5
Some form of patient navigation, including telephonic or virtual navigation using automated electronic messaging, is suggested to improve rates of adequate bowel preparation, according to the American Gastroenterological Association 5

For patients with previous inadequate bowel preparation, modifications should include increased attention to communicating preparation instructions, as recommended by the American Gastroenterological Association 5
Adding promotility agents can be considered for patients with previous inadequate bowel preparation, according to the American Gastroenterological Association 1

Bowel preparation quality should be assessed only after all washing and suctioning have been completed, as recommended by the American Gastroenterological Association 1
Endoscopy units should track bowel preparation adequacy rates, with a target of 90% at both individual endoscopist and unit levels, according to the American Gastroenterological Association 1

When bowel preparation is inadequate, colonoscopy should be rescheduled within 12 months for screening or surveillance colonoscopies, as recommended by the American Gastroenterological Association 1
Same-day salvage maneuvers can be used when feasible for inadequate bowel preparations, according to the American Gastroenterological Association 1