Systematic review and meta-analysis: sodium picosulfate/magnesium citrate vs. polyethylene glycol for colonoscopy preparation

Background and aims Previous studies comparing sodium picosulfate/magnesium citrate (SPMC) with polyethylene glycol (PEG) drew inconsistent conclusions. We conducted a meta-analysis to compare the performance of the two agents for colonoscopy preparation. Methods A search of randomized controlled trials (RCTs) up to July 2015 was acquired, using MEDLINE, EMBASE, the Cochrane Library, and Google Scholar. We calculated the pooled estimates of bowel cleanliness, polyp/adenoma detection rate (PDR/ADR), completion of preparation, willingness to repeat identical bowel preparation, and adverse events by using relative risk (RR) with random-effects models. A non-inferiority analysis was performed, comparing SPMC to PEG for bowel cleaning efficacy. Results A total of 25 RCTs were qualified for analysis. There was no statistically significant difference between the two agents in bowel cleanliness, but the effect direction showed a trend in favor of PEG (RR 0.93; 95 % CI 0.86–1.01, P = 0.07). The non-inferiority analysis demonstrated the non-inferiority of SPMC by retaining at least 90 % of the effect of PEG. Similarly, there was no significant difference between the two agents in PDR (RR 0.94; 95 % CI 0.82–1.08, P = 0.37) and ADR (RR 0.88; 95 % CI 0.74–1.05, P = 0.16). However, a higher proportion of patients were likely to complete SPMC preparation (RR 1.08; 95 % CI 1.04–1.13, P < 0.001) and were willing to repeat SPMC preparation (RR 1.44; 95 % CI 1.25–1.67, P < 0.001). The total number of adverse events was significantly lower in the SPMC group (RR 0.78; 95 % CI 0.66–0.93, P = 0.004). Conclusions SPMC, with better tolerability and less frequent adverse events, demonstrated non-inferior bowel cleaning efficacy than that of the PEG. Large-scale, well-organized, head-to-head studies are warranted.