Oral sulfate solution versus low‐volume polyethylene glycol for bowel preparation: Meta‐analysis of randomized controlled trials

Oral sodium sulfate (OSS) solution and low-volume polyethylene glycol-based solutions are two of the more common low-volume purgatives used as colonoscopy preparations. Data on how these different low-volume solutions compare are mixed. Our aim was to conduct a meta-analysis of randomized controlled trials (RCTs) to compare OSS with low-volume polyethylene glycol solutions (PEG) plus ascorbic acid (PEG + Asc) solution with respect to (i) satisfactory bowel preparation, (ii) excellent bowel preparation, and (iii) tolerability.Studies were identified by searching 10 medical databases for reports published from 1974 until 2019. Only fully published RCTs comparing OSS and low-volume PEG-based products with regard to overall satisfactory bowel preparation were included. Pooling was conducted by both fixed-effects and random effects models; results are presented from the random effects model when heterogeneity was significant.Seven studies (involving 2049 subjects) met the inclusion criteria. There was no difference between OSS and PEG + Asc with respect to adequate bowel preparation (risk ratio [RR] 1.02 [0.99-1.06]; P = 0.16). OSS did result in a higher chance of excellent bowel preparation (RR 1.18 [1.06-1.31]; P = 0.03). OSS was associated with a 30% increased risk of nausea (RR 1.35 [1.03-1.77]; P = 0.03) and more than double the risk of vomiting (RR 2.30 [1.63-2.23]; P 0.05) compared with PEG + Asc. Begg's funnel plot indicated low probability of publication bias.Individuals at low risk of inadequate bowel preparation who use OSS for bowel preparation are more likely to achieve excellent bowel preparation, but are more likely to experience nausea and vomiting than are individuals using low-volume PEG-based solutions.