The importance of colonoscopy bowel preparation for the detection of colorectal lesions and colorectal cancer prevention

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.

Fig. 1

Select colonoscopy quality indicators . ADR, adenoma detection rate. ^* Rate at which outpatient bowel preparation is suitable for using recommended surveillance or screening intervals. ^† Percentage of screening colonoscopies performed in average-risk asymptomatic individuals aged ≥ 50 years in which ≥ 1 adenoma has been detected. ^‡ Percentage of screening colonoscopies with successful cecal intubation and photographic evidence of cecal landmarks. ^§ Average withdrawal time in screening colonoscopies with negative results. Figure created with data from Rex DK, et al. Gastrointest Endosc 2015; 81: 31–53.

Fig. 2

Colon anatomy.