Review for 10.1186/s12876-020-01457-y (2020)

Reviewer ’s report  
 
Title: Underwater versus conventional endoscopic mucosal resection  for small size 
nonpedunculated colorectal  polyps：A randomized controlled trial  
 
Version: 0 Date: 10 May 2020  
 
Reviewer's report:  
 
10 May 2020  
 
Dear Authors  
 
Thank you for giving me the opportunity to review.  
The authors investigated and demonstrated the utili ty and safety of UEMR for small colorectal 
polyps in a multicenter prospective study comparing conventional EMR results.  
This is the first study and well -designed, therefore, it is considered to be valuable.  
However, there are a few things to consider.  
The points I would like to point out are shown below.  
 
Major  
1. Definition of "complete resection" is uncertain. Please describe in detail in the 
"Method" section. Did you do pathological examination of the specimens resected by UEMR and 
CEMR?  
   (e.g. comple te resection was defined as en bloc resection with a histologically confirmed 
negative.)  
 
2. In your study, patients were randomized to CEMR or UEMR, and some patients had 
multiple polyps. The authors analyzed delayed bleeding at each polyp, but how did the patients 
who underwent EMR for multiple polyps were evaluated postoperative bleeding? Pleas e describe 
the method clearly.  
 
Minor  
1. (Figure2)  
Is the description "Encluded" in Figure 2 not "Excluded"?  
Please check it.  
2. (P4 line 76)  
There are two periods at the end of the sentence.  
3. (Figure 2 and Tables)  
The placements of CEMR and UEMR in th e Figure and Tables should be the same. (In your 
paper, UEMR in the figure on the left, UEMR is right in the tables.)  
 
Tomoaki Matsumura, MD., Ph.D.  
Department of Gastroenterology  
Graduate School of Medicine, Chiba University, Inohana 1 -8-1, Chiba, 2608670 , Japan.  
matsumura@chiba -u.jp 
Telephone: +81 -43-2262083  
Fax: +81 -43-2262088  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
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, please 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:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing i nterests, considering the following questions:  
 
1.  Have you in the past five years received reimbursements, f ees, funding, or salary 
from an organisation that may in any way gain or lose financial ly from the 
publication 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 currently applying for any patents relating to t he 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 h ave no competing interests.  
 
Reviewer Publication Consent. I agree for my report to be made  available under a n Open 
Access Creative Commons CC -BY License ( http://creativecommons.org/licenses/by/4.0 ) if this 
manuscript is accepted for publication. Any commen ts that I do not wish to be included in the 
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I agree to the terms of the CC -BY 4.0 license; please do not publish my name with my report.  
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