Comparison between large volume and osmotic agent lavage for optimal colonoscopy bowel cleansing, randomizing adult outpatients by invitation letter

This randomized quality assurance trial aims to compare cleansing quality of two different principles of colonoscopy lavage. Large volume PEG solutions are considered safe, but cumbersome and inpalatable, while osmotic solutions are generally more acceptable, however, the risk of electrolyte disturbances or renal decompensation may increase.

The study will focus on patient experience and compliance, as well as cleansing quality, endoscopic findings and other technical parameters of the colonoscopy procedure that may be adversely affected by poor bowel cleansing. Three centers will participate, ensuring a diverse patient population. 800 patients are planned for recruitment, but an interim assessment of statistics of the primary aim parameter (bowel cleansing) will be performed to adjust the number.

Inclusion Criteria:

• Pts for out-patient colonoscopy
• age 18-80

Exclusion Criteria:

• Active colitis or suspicion thereof (bloody diarrhea, fever and abdominal pain)
• Suspicion of renal insufficiency or ileus/subileus
• Previous colonic surgery
• Pregnancy
• Inability to adhere to cleansing instructions
• Inability to consent