What is the recommended bowel prep regimen for a standard colonoscopy?

From the Guidelines

The recommended bowel prep regimen for a standard colonoscopy typically involves a split-dose polyethylene glycol (PEG) solution, with half (2 liters) consumed the evening before the procedure and the remaining half completed 4-6 hours prior to the colonoscopy, finishing at least 2 hours before the appointment, as supported by the most recent and highest quality study 1.

Key Points to Consider

• The split-dose method is preferred because it improves the quality of bowel cleansing, especially for the right side of the colon, resulting in better polyp detection rates 1.
• Common PEG preparations include GoLYTELY, MoviPrep, or MiraLAX mixed with Gatorade.
• Prior to starting the prep, follow a clear liquid diet the entire day before the procedure, avoiding red, purple, or blue liquids which can interfere with visualization, as recommended by the US Multi-Society Task Force on Colorectal Cancer 1.
• In the days leading up to the colonoscopy, avoid high-fiber foods, seeds, nuts, and raw vegetables.
• Take any prescribed medications as directed, but stop iron supplements and blood thinners as advised by your doctor.
• Adequate hydration throughout the prep process is essential to prevent dehydration and electrolyte imbalances.
• A same-day regimen is an acceptable alternative to split dosing for individuals undergoing an afternoon colonoscopy, but the split-dose regimen is preferred for morning colonoscopies 1.

Benefits of the Recommended Regimen

• Improves the quality of bowel cleansing, especially for the right side of the colon.
• Results in better polyp detection rates.
• Is well-tolerated by most patients.
• Can be completed with minimal disruption to daily activities.

Important Considerations

• Patients with certain medical conditions, such as kidney disease or heart failure, may need to use alternative bowel prep regimens.
• Patients with a history of inadequate bowel prep or colonoscopy cancellation due to inadequate prep may require additional guidance and support to ensure adequate bowel cleansing.
• The use of adjunctive agents, such as simethicone, may be considered to improve bowel prep quality, but the evidence for their effectiveness is limited 1.

From the Research

Bowel Prep Regimens for Colonoscopy

The recommended bowel prep regimen for a standard colonoscopy can vary depending on the specific requirements and patient factors. Some studies have compared different bowel prep regimens, including:

• Polyethylene glycol (PEG) solutions, such as full-dose or split-dose regimens 2
• Sodium picosulphate with magnesium citrate (SPS-Mg) versus sulphate-free polyethylene glycol electrolyte lavage (PEG-EL) solution 3
• Sodium phosphate (NaP) tablets versus split-dose PEG 4
• Combination of 2 L polyethylene glycol and sodium phosphate solution versus conventional 4 L polyethylene glycol or split method of 4 L polyethylene glycol 5
• Low-volume split-dose polyethylene glycol electrolytes solution bowel preparation regimens 6

Efficacy and Tolerability of Bowel Prep Regimens

Studies have shown that:

• Split-dose PEG can improve the quality of bowel preparation and patient compliance compared to full-dose PEG 2
• SPS-Mg can be better tolerated and result in higher quality bowel cleansing compared to PEG-EL 3
• NaP tablets can be as effective as PEG in terms of colon cleansing and may improve patient compliance and ease of administration 4
• Low-volume split-dose regimen two can have superior bowel-cleansing efficacy and patient tolerability compared to low-volume split-dose regimen one 6

Factors to Consider

When selecting a bowel prep regimen, factors to consider include:

• Patient compliance and tolerance
• Quality of bowel preparation
• Safety and potential side effects
• Ease of administration and patient preference
• Specific requirements for the colonoscopy procedure, such as morning or afternoon scheduling 5, 6