Goals: To compare the efficacy and tolerability of morning-only polyethylene glycol (PEG) with split-dose preparation in hospitalized patients scheduled for colonoscopy.

Background: Morning-only colonoscopy preparation may improve efficiency by allowing patient preparation and colonoscopy to be performed on the same day. There are limited data comparing morning-only with split-dose preparation, and more studies are needed before morning-only preparation can be routinely recommended.

Study: A single-center, prospective, endoscopist-blinded study was conducted, in which hospitalized patients scheduled to undergo diagnostic colonoscopy were randomly assigned to receive 4 L of PEG either on the morning of colonoscopy or as a split-dose (evening-morning). The primary endpoint was efficacy of bowel preparation measured by the Ottawa scale. Secondary endpoints were patient compliance and tolerance.

Results: A total of 120 hospitalized patients scheduled for diagnostic colonoscopy were randomized. The mean total Ottawa score was slightly superior for the morning-only arm, and the upper bound of 95% confidence interval (CI) for difference between arms was less than our prespecified noninferiority margin of 1.5 (difference=−0.23; 95% CI, −1.72 to 1.25). The percentage of patients with good bowel preparation was similar for all colonic segments. There was a trend toward more side effects among patients in the morning-only compared with the split-dose arm (71% vs. 54%; P=0.08). Compared with morning-only preparation, more patients in the split-dose arm were willing to undergo similar preparation for future colonoscopies (71% vs. 89%; P=0.02).

Conclusions: Morning-only PEG is not inferior to split-dose preparation regarding bowel cleansing efficacy for colonoscopy in hospitalized patients. However, split-dose preparation was preferred by patients because of less side effects.