Same-day Versus Split-dose Bowel Preparation Before Colonoscopy: A Meta-analysis.

BACKGROUND: Split-dose regimens (SpDs) were recommended as a first choice for bowel preparation, whereas same-day regimens (SaDs) were recommended as an alternative; however, randomized trials compared them with mixed results. The meta-analysis was aimed at clarifying efficacy level between the 2 regimens. MATERIALS AND METHODS: We used MEDLINE/PubMed, EMBASE, Scopus, CINAHL, Cochrane Library, and Web of Science to identify randomized trials published from 1990 to 2016, comparing SaDs to SpDs in adults. The pooled odds ratios (ORs) were calculated for preparation quality, cecal intubation rate (CIR), adenoma detection rate (ADR), and any other adverse effects. RESULTS: Fourteen trials were included. The proportion of individuals receiving SaDs and SpDs with adequate preparation in the pooled analysis were 79.4% and 81.7%, respectively, with no significant difference [OR=0.92; 95% confidence interval (CI), 0.62-1.36] in 11 trials. Subgroup analysis revealed that the odds of adequate preparation for SaDs with bisacodyl were 2.45 times that for SpDs without bisacodyl (95% CI, 1.45-4.51, in favor of SaDs with bisacodyl). Subjects received SaDs experienced better sleep. CONCLUSIONS: SaDs were comparable with SpDs in terms of bowel cleanliness, CIR, and ADR, and could also outperform SpDs in preparation quality with bisacodyl. SaDs also offered better sleep the previous night than SpDs did, which suggests that SaDs might serve as a superior alternative to SpDs. The heterogenous regimens and measurements likely account for the low rates of optimal bowl preparations in both arms. Further studies are needed to validate these results and determine the optimal purgatives and dosages.