Preprocedural Fluid and Nutrition Management

Perioperative Fasting Guidelines

The American Society of Anesthesiologists recommends that patients can drink clear liquids until 2 hours before endoscopy, while solid foods should be withheld for at least 6 hours before the procedure 1, 2
Clear liquids, such as water, clear juices, and black coffee, can be consumed until 2 hours before endoscopy 2
Solid foods should be withheld for at least 6 hours before the procedure, as should milk and infant formula, which can delay gastric emptying 1, 2
Breast milk should be withheld for at least 4 hours before the procedure 2

Patients taking GLP-1 receptor agonists, such as semaglutide, may require a longer fasting period due to an increased risk of retained gastric contents 3
Patients at high risk of aspiration may require longer fasting periods 2

A split-dose bowel preparation regimen is recommended, with the second dose starting 4-6 hours before colonoscopy and completing at least 2 hours before the procedure 4, 5
Same-day bowel preparation may be considered for afternoon colonoscopies 4, 6

Prolonged preoperative fasting from midnight is unnecessary for most patients 1, 7
Preoperative carbohydrate loading (carbohydrate drink the night before and 2 hours before surgery) may be beneficial in reducing postoperative insulin resistance 8
Nutritional support should be considered before major surgical procedures for patients at nutritional risk 1, 7