Restellini S, et al. – This meta–analysis strived to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon–cleansing products in patients with inflammatory bowel disease. Polyethylene glycol (PEG) low–volume regimen seemed not inferior to PEG high–volume to clean the colon in inflammatory bowel disease population, and yielded improved willingness–to–repeat. To compare contemporary products in this population, further additional research was urgently required.

• Between January 1980-September 2016, the authors performed systematic searches using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge for randomized trials assessing preparations with or without adjuvants, given in split and non-split dosing, and in high (> 3 L) or low-volume (2 L or less) regimens.
• The primary outcome was bowel cleansing quality.
• Patient willingness-to-repeat the procedure and side effects/complications were included as secondary outcomes.

• The inclusion criteria was fulfilled by 4 trials (n = 449 patients) among 439 citations.
• With no effect on bowel cleansing quality, 1 trial evaluated the effect of adding simethicone to polyethylene glycol (PEG) 4 L, but a better tolerance.
• Again without any differences in term of bowel cleansing, another trial compared senna to castor oil.
• In this study, 2 trials compared the efficacy of PEG high-volume vs PEG low-volume associated to an adjuvant in split-dose regimens: PEG low-dose efficacy was not different to PEG high-dose; OR = 0.84 (0.37-1.92).
• Compared to high-volume, a higher proportion of patients were willing to repeat low-volume preparations; OR = 5.11 (1.31-20.0).