Change in title: The title was changed to highlight the fact that this is a review of polymer‐based ORS (not glucose‐based ORS).

New author: EG Martinez joined the author team after the protocol was published.

Data extraction: We originally planned to extract count data by determining the total number of episodes in each group (if the episode is rare) or the number of person years in each group for each treatment arm (if the episode is common). However, during the assessment of the trials, the trials reported the number of participants with unscheduled use of intravenous fluid, and thus it was considered to be a dichotomous rather than a count outcome. Similarly, in the data extraction for number of episodes of vomiting, there were only four trials that reported this outcome, while nine clinical trials reported the number of participants with vomiting. It was decided that the latter would be reported. Other adverse effects that were reported in the trials, including number of participants with hypokalaemia (low potassium levels) and those with development of persistent diarrhoea (diarrhoea of more than 10 days' duration from onset), were also included in the review.

Data analysis: In multiple treatment arms with two or more polymer‐based ORS as treatment groups, the outcomes were combined as appropriate and compared collectively with the control group. Most of the trials included both cholera and non‐cholera cases, and this group was collectively termed as having mixed pathogens rather than non‐cholera related diarrhoea.

Subgroup analyses: These were limited to the osmolarity of the glucose ORS, the type of polymer, and the effects of participant's age and pathogen. The source of the polymer and the effect of feeding were no longer evaluated as most of the polymers were locally prepared and all but two trials withheld feeding after hydration.

Publication bias: The presence of publication bias was confirmed with StatsDirect, a statistical software program.