Review for 10.1186/s12876-020-01220-3 (2020)

Reviewer ’s report  
 
Title: Effectiveness of concomitant use of green tea and polyethyl ene glycol in bowel 
preparation for colonoscopy: A randomized control led study  
 
Version: 1 Date: 23 Nov 2019  
 
Reviewer: Lawrence Hookey  
 
Reviewer's report:  
Please include all comments for the authors in this box rather than uploading your repor t as an 
attachment. Please only upload as attachments annotated versions of manuscripts, graphs, 
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Please overwrite this text when adding your comments to the aut hors.  
 
The authors have revised the paper according to reviewers' feedback.  
Regarding the new explanation for the power calculation, I question why a one sided t -test was 
used. There was certainly no guarantee that the intervention would be better or equiv alent, thus 
the research ran a significant risk of being underpowered. As it so happened, the control group's 
complete consumption rate was much less than assumed, and this allowed room for improvement 
with the intervention.  
With regards to the p value, I  was only suggesting that the specific values listed as 0.000 be 
changed to less than 0.0001, as the specific value was not 0.000.  
 
Are the methods appropriate and well described?  
If not, please specif y what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the  data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, pleas e speci fy what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
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financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you curr ently applying for any patents  relating to the content of the 
manuscript?  
 
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holds  or has applied for patents relating to the content of the manuscript?  
 
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below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests.  
 
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