The U.S. Multi-Society Task Force on Colorectal Cancer has released updated recommendations for optimizing bowel preparation for colonoscopy. This represents a joint effort by the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy.

Published in the March 2025 issue of The American Journal of Gastroenterology, the guidelines provide 25 evidence-based recommendations to ensure adequate visualization during colonoscopy. They also allow for standard screening or surveillance intervals to be assigned based on findings.

Key Recommendations

Patient Education and Navigation

• Provide both verbal and written patient education instructions for all components of colonoscopy preparation (strong recommendation, high-quality evidence)
• Offer patient navigation, including telephonic or virtual navigation using automated electronic messaging (weak recommendation, moderate-quality evidence)

Dietary Modifications

• Limit dietary modifications to the day before colonoscopy for ambulatory patients at low risk for inadequate bowel preparation (strong recommendation, high-quality evidence)
• Use low-residue/low-fiber foods or full liquids for early and midday meals on the day before colonoscopy when using split-dose regimens (strong recommendation, high-quality evidence)

Bowel Preparation Regimens

• No single purgative is superior for ambulatory patients at low risk for inadequate preparation (strong recommendation, high-quality evidence)
• Consider 2L bowel preparation regimens instead of 4L regimens (weak recommendation, moderate-quality evidence)
• Select preparation regimens based on medical history, medications, and prior preparation adequacy (strong recommendation, moderate-quality evidence)
• Avoid hyperosmotic regimens in individuals at risk for volume overload or electrolyte disturbances (strong recommendation, high-quality evidence)

Preparation Timing

• Use split-dose administration for all patients, regardless of preparation volume (strong recommendation, high-quality evidence)
• Same-day regimen is acceptable for afternoon colonoscopy (strong recommendation, high-quality evidence)
• Same-day regimen is inferior for morning colonoscopy (weak recommendation, low-quality evidence)
• For split-dose regimens, begin the second portion 4 to 6 hours before colonoscopy and complete at least 2 hours before the procedure (strong recommendation, moderate-quality evidence)

Adjunctive Agents

• Consider oral simethicone for bowel preparation (weak recommendation, moderate-quality evidence)
• Routine use of nonsimethicone adjuncts is not recommended (weak recommendation, low-quality evidence)

During Colonoscopy

• Insert colonoscope to sigmoid colon to confirm inadequacy before aborting for reported incomplete preparation (weak recommendation, low-quality evidence)
• Assess bowel preparation quality after washing and suctioning, using reliably understood descriptors (strong recommendation, moderate-quality evidence)
• Use the term "adequate bowel preparation" to indicate standard intervals can be assigned (strong recommendation, moderate-quality evidence)
• Consider irrigation pumps to assist with bowel preparation (weak recommendation, very low-quality evidence)
• Use same-day salvage maneuvers when feasible for inadequate preparations (weak recommendation, moderate-quality evidence)

Quality Measurement

• Track rate of adequate preparations at individual endoscopist and endoscopy unit levels (strong recommendation, moderate-quality evidence)
• Target bowel preparation adequacy rate of 90% or higher (strong recommendation, moderate-quality evidence)

Managing Inadequate Preparation

• Reschedule colonoscopy within 12 months for screening or within 3 months for abnormal screening tests (strong recommendation, moderate-quality evidence)
• After inadequate preparation, modify instructions to include increased communication, navigation, diet restrictions, promotility agents, constipation treatment, medication cessation, and/or high-volume preparations (strong recommendation, moderate-quality evidence)
• Manage individuals at high risk like those with prior inadequate preparation (strong recommendation, moderate-quality evidence)
• For high-risk individuals, consider split-dose 4L polyethylene glycol-electrolyte lavage solution with bisacodyl and modified diet (weak recommendation, low-quality evidence)

The Task Force emphasized the importance of tracking and measuring bowel preparation adequacy rates, with a specific quality target of 90% or greater at both endoscopist and endoscopy unit levels. Clear pathways for rescheduling and modified preparation regimens are provided for patients with inadequate preparation.

These guidelines represent a comprehensive update to the 2014 recommendations, developed following a thorough literature review and consensus among experts from the three major GI societies.