Bowel preparation with split-dose polyethylene glycol before colonoscopy: a meta-analysis of randomized controlled trials. Kilgore TW, Abdinoor AA, Szary NM, Schowengerdt SW, Yust JB, Choudhary A, Matteson ML, Puli SR, Marshall JB, Bechtold ML. Gastrointest Endosc. 2011 Jun;73(6):1240-5. BACKGROUND: Polyethylene glycol (PEG) is a commonly used bowel preparation for colonoscopy. Unfortunately, the standard large-volume solution may reduce patient compliance. Split-dosing of PEG has been studied in various randomized, controlled trials (RCTs). However, results have been conflicting. OBJECTIVE: We conducted a meta-analysis to assess the role of split-dose PEG versus full-dose PEG for bowel preparation before colonoscopy.DESIGN: Multiple databases were searched (January 2011). RCTs on adults comparing full-dose and split-dose of PEG for bowel preparation before colonoscopy were included and analyzed by calculating pooled estimates of quality of bowel preparation, preparation compliance, willingness to repeat the same preparation, and side effects by using odds ratio (OR) by fixed and random-effects models. SETTING: Literature search. PATIENTS: Per RCTs. MAIN OUTCOME MEASUREMENTS: Satisfactory bowel preparation, willingness to repeat same bowel preparation, patient compliance, and side effects. RESULTS: Five trials met inclusion criteria (N = 1232). Split-dose PEG significantly increased the number of satisfactory bowel preparations (OR 3.70; 95% CI, 2.79-4.91; P < .01) and willingness to repeat the same preparation (OR 1.76; 95% CI, 1.06-2.91; P = .03) compared with full-dose PEG. Split-dose PEG also significantly decreased the number of preparation discontinuations (OR 0.53; 95% CI, 0.28-0.98; P = .04) and nausea (OR 0.55; 95% CI, 0.38-0.79; P < .01) compared with full-dose PEG. LIMITATIONS: Limited number of studies. CONCLUSIONS: The use of a split-dose PEG for bowel preparation before colonoscopy significantly improved the number of satisfactory bowel preparations, increased patient compliance, and decreased nausea compared with the full-dose PEG.