How many hours should a patient be NPO (nothing by mouth) before a capsule endoscopy?

NPO Requirements for Capsule Endoscopy

Patients should fast for at least 12 hours prior to capsule endoscopy. 1

Detailed Fasting Requirements

The European Crohn's and Colitis Organisation (ECCO) guidelines provide clear recommendations regarding fasting requirements before capsule endoscopy:

• Complete fasting from solid foods for at least 12 hours before the procedure 1
• No liquid consumption for at least 4 hours before the procedure 1
• After capsule ingestion:
  • Clear liquids may be taken after 2 hours
  • Food and medications may be taken after 4 hours 1

Bowel Preparation Recommendations

In addition to fasting requirements, bowel preparation is strongly recommended to improve visualization quality:

• The use of bowel preparation is recommended as it improves visualization and diagnostic yield 1
• Polyethylene glycol (PEG) preparation is most commonly used:
  • Half dose (1L), low volume (2L), or high volume (4L) PEG has been shown to be beneficial 1
  • 2L of PEG solution is as effective as 4L in terms of small bowel visualization quality and diagnostic yield 2
• Adding simethicone to the bowel preparation regimen can enhance small bowel visualization quality 2

Special Considerations

Patients with Poor GI Motility

• For patients with poor GI motility or chronic narcotic use, confirm that the capsule has reached the small bowel within 1 hour of ingestion 3
• Continue the study for the full extent of the battery life of the capsule 3

Risk of Capsule Retention

• The risk of capsule retention is 1.4-2% overall, but higher (5.2-13%) in patients with established IBD 3
• High-risk patients (known or suspected intestinal strictures, history of obstructive symptoms, known Crohn's disease, etc.) should undergo pre-procedure evaluation 3
• Cross-sectional imaging or patency capsule testing may be indicated for high-risk patients 3

Practical Approach

1. Schedule the procedure in the morning
2. Instruct patient to begin fasting from solid foods at least 12 hours before the procedure
3. Stop all liquid intake 4 hours before the procedure
4. Administer bowel preparation with PEG solution (preferably 2L)
5. Consider adding simethicone to improve visualization
6. After capsule ingestion, allow clear liquids after 2 hours and food/medications after 4 hours

Common Pitfalls to Avoid

• Inadequate fasting time: Insufficient fasting can lead to poor visualization and potentially missed lesions
• Overlooking high-risk patients: Failure to identify patients at risk for capsule retention can lead to complications requiring endoscopic or surgical intervention
• Ignoring poor motility: In patients with poor GI motility, failure to confirm capsule passage into the small bowel can result in incomplete examinations

While some studies suggest that prolonged fasting alone without bowel preparation might be adequate for small bowel visualization 4, the strongest evidence supports the combination of proper fasting (12 hours) and bowel preparation for optimal results.