Review for 10.1186/s12876-022-02484-7 (2022)

Reviewer’s report
Title: 
Transient alterations in plasma sodium concentrations with NER1006
bowel preparation: an analysis of three phase III, randomized clinical trials
Version: 
0 
Date: 
19 Jan 2022
Reviewer's report:
"PEER REVIEWER ASSESSMENTS: 
OBJECTIVE - Full research articles: is there a clear objective that addresses a
testable research question(s) (brief or other article types: is there a clear
objective)?
Yes - there is a clear objective
DESIGN - Is the current approach (including controls and analysis protocols)
appropriate for the objective?
Yes - the approach is appropriate
EXECUTION - Are the experiments and analyses performed with technical rigor
to allow confidence in the results?
Yes - experiments and analyses were performed appropriately
STATISTICS - Is the use of statistics in the manuscript appropriate?
Yes - appropriate statistical analyses have been used in the study
INTERPRETATION - Is the current interpretation/discussion of the results
reasonable and not overstated?
Yes - the author's interpretation is reasonable
OVERALL MANUSCRIPT POTENTIAL - Is the current version of this work
technically sound? If not, can revisions be made to make the work technically
sound?
Probably - with minor revisions
PEER REVIEWER COMMENTS: 
GENERAL COMMENTS: 
The present manuscript compares the changes in the sodium concentrations
found in plasma after treatment with a cleansing solution known as NER1006, as
preparation for colonoscopy. With this aim, the authors characterize the results
of three registered clinical trials, comparing blood levels at baseline and at
certain time points after treatment. 
The authors have carefully considered the selection of trials with different
conditions, and comprising the same time points for comparison. They have
included a high number of individuals (1028 in total), and defined clear criteria
for inclusion in the study.
The only thing I miss in this study is an initial figure clarifying the arms of the
study and the cohorts (see comment below).
ADDITIONAL REQUESTS/SUGGESTIONS: 
Given that the study includes cohorts of three different trials, under slightly
different conditions of administration of the cleansing solution, it would be
really helpful for the reader to include a first figure with a representation of the
three arms. For each of them, the total number of patients in the original study,
the ones selected/excluded in the metanalysis, the number of individuals found
to have hypernatremia, and the cases considered clinically relevant (adverse
effects, even if short and not acute)."
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Declaration of competing interests
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interests, considering the following questions:
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. 
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Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
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Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
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Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes