Sodium phosphate versus polyethylene glycol for colonoscopy bowel preparation: an updated meta-analysis of randomized controlled trials

Adequate bowel cleansing is of great importance for a high-quality colonoscopy examination. Nevertheless, whether sodium phosphate or polyethylene glycol is a gold standard agent for bowel preparation is still under debate. In consideration of the clinical needs, we thus performed an updated meta-analysis of randomized controlled trials concerning the comparison between both regimens. The efficacy, safety and acceptability of each regimen are major indicators to measure and appraise. By searching PubMed, EMBASE, Web of Science and Cochrane Library databases, 15 original trials published from 2000 to 2014 were included as eligible studies. We carried out data extraction and subsequent pooling analysis for each indicator in a standard manner. Sensitivity analysis was performed by elimination of low-quality trials, while a funnel plot and Egger's test were employed to analyze the publication bias across studies. Our pooling analysis revealed that patients undergoing sodium phosphate as a cleansing agent displayed better acceptability, compliance, cleansing scores, preparation taste, polyp detection rate and less adverse effects including nausea, vomiting and abdominal pain (P < 0.05). In terms of procedure time, adequate preparation rate and electrolyte concentration, there was no significant difference between both regimens (P > 0.05). The pooling analysis offered stable conclusions which were verified by our sensitivity analysis. There was no publication bias across studies as a symmetric funnel plot was demonstrated and the result of Egger's test was P = 0.56. Regarding preparation efficacy, safety and acceptability, sodium phosphate was a better agent than polyethylene glycol for colonoscopy bowel cleansing, with its advantages of higher efficacy, better tolerability and acceptability as well as comparable safety.