Abstract
Background and study aims Colonoscopy for colorectal cancer (CRC) screening has reduced CRC incidence and mortality
and improved prognosis. Optimal bowel preparation and high-quality endoscopic technique
facilitate early CRC detection.
This review provides a narrative on the clinical importance of bowel preparation for
colonoscopy and highlights available bowel preparations.
Methods A PubMed search was conducted through June 2019 to identify studies evaluating clinical
outcomes, efficacy, safety, and tolerability associated with bowel preparation for
CRC screening-related colonoscopy.
Results Selecting the optimal bowel preparation regimen is based on considerations of efficacy,
safety, and tolerability, in conjunction with individual patient characteristics and
preferences. Available bowel preparations include high-volume (4 L) and low-volume
(2 L and 1 L), polyethylene glycol (PEG) solutions, sodium sulfate, sodium picosulfate/magnesium
oxide plus anhydrous citric acid, sodium phosphate tablets, and the over-the-counter
preparations magnesium citrate and PEG-3350. These preparations may be administered
as a single dose on the same day or evening before, or as two doses administered the
same day or evening before/morning of colonoscopy. Ingesting at least half the bowel
preparation on the day of colonoscopy (split-dosing) is associated with higher adequate
bowel preparation quality versus evening-before dosing (odds ratio [OR], 2.5; 95 %
confidence interval [CI], 1.9−3.4).
Conclusions High-quality bowel preparation is integral for optimal CRC screening/surveillance
by colonoscopy. Over the last 30 years, patients and providers have gained more options
for bowel preparation, including low-volume agents with enhanced tolerability and
cleansing quality that are equivalent to 4 L preparations. Split-dosing is preferred
for achieving a high-quality preparation.
