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: 0 Date: 13 Sep 2019  
 
Reviewer: Argyrios Ioannidis  
 
Reviewer's report:  
I had the pleasure to review the article titled "Effectiveness of concomitant use of green tea and 
polyethyl ene glycol in bowel preparation for colonoscopy: A randomized controlled study" and i 
would like to applaud the authors of the article for their efforts. This article is a prospective 
randomized controlled single blind trial which aimed to assess the effec tiveness and safety of the 
addition of green tea along with polyethylene glycol prior to colonoscopy for bowel preparation.  
 
My comments can be found below:  
1) In the abstract the word awful needs to be changed as it doesnt really represent a scientific and 
academic style of writing. I would recommend changing to " uncomfortable" taste  
2) The authors need to explain why they excluded patients with previous abdom inal operations.  
3) This study seems like a superiority randomized controlled trial and the authors need to explain 
if the statistics employed were chosen to try to prove the superiority of green tea addition to PEG 
when compared to PEG alone as bowel prepa ration method.  
4) Why was the study retrospectively registered?  
5) Did the authors acquire a statistical power analysis before the randomization process?  
 
 
 
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:  
 
Needs some language corrections before being published  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisation that may in any way gain or lose financially from the publi cation of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation t hat may in any way gain or lose 
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?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any  other financial competing interests?  
 
6. 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.  
 
I declare that I have no competing interests.  
 
 
 
 
 
I agree to the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted for publication, my named repo rt 
including any attachments I upload will be posted on the website  along with the authors' 
responses. I agree for my report to be made available under an Open Access Creative Commons  
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal