When should a patient with normal gastrointestinal function stop drinking clear liquids before undergoing a capsule endoscopy?

Clear Liquid Fasting Before Capsule Endoscopy

Patients should stop drinking clear liquids 2 hours before capsule endoscopy, following standard anesthesia fasting guidelines. 1

Recommended Fasting Protocol

The ECCO-ESGAR guidelines for capsule endoscopy in IBD explicitly state that following capsule ingestion with water, clear liquids may be taken after 2 hours and food and medications may be taken after 4 hours. 1 This recommendation aligns with the 2023 American Society of Anesthesiologists practice guidelines, which permit clear liquids up to 2 hours before procedural sedation for healthy patients undergoing elective procedures. 1

Pre-Procedure Fasting Requirements

• Patients should fast for at least 12 hours prior to capsule ingestion to ensure adequate visualization of the small bowel. 1

• Clear liquids should be stopped 2 hours before the capsule endoscopy procedure if sedation or anesthesia will be used. 1, 2

• This 2-hour clear liquid cutoff is supported by evidence showing no excess gastric volumes when patients complete bowel preparations or consume clear liquids up to 2 hours before endoscopy. 1

Bowel Preparation Considerations

• Bowel preparation with polyethylene glycol (PEG) is recommended as it improves visualization and diagnostic yield, though half-dose (1 L), low-volume (2 L), or high-volume (4 L) preparations have all shown benefit. 1

• The addition of simethicone to the preparation regimen is recommended as it enhances small bowel visualization quality. 1

• Research demonstrates that clear liquid diet alone (without purgative preparation) is sufficient and better tolerated by patients, though guidelines still favor some form of bowel preparation. 3, 4

Important Caveats

• Patients with conditions that delay gastric emptying require individualized assessment, including those on GLP-1 receptor agonists, with diabetes, gastroparesis, or significant reflux disease. 1, 2 The ASA advises stopping GLP-1 agonists for 1-7 days before elective procedures. 1

• The 2-hour clear liquid rule applies to "healthy patients" without coexisting conditions that increase aspiration risk such as esophageal disorders, previous gastric surgery, gastrointestinal obstruction, pregnancy, or obesity. 1

• Evidence from gastric volume studies shows that residual gastric fluid volume was actually lower (11 mL vs 19 mL) when patients consumed clear liquids closer to procedure time compared to longer fasting periods. 1, 2