Review for 10.1186/s12876-020-01256-5 (2020)

Reviewer’s report
Title: Prostaglandin E-major urinary metabolite versus fecal immunochemical occult blood test as a
biomarker for patient with ulcerative colitis
Version: 1 Date: 01 Dec 2019
Reviewer: Isao Okayasu
Reviewer's report:
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Major comments
1.PGE-MUM reflects the inflammation status of a whole colon. Mucosal healing is important for
patients with UC to maintain remission. Accordingly, authors should show the correlation of PGE-
MUM or FIT to the sum of eMayo calculated from 6 segments (the cecum, ascending colon, transverse
colon, descending colon, sigmoid colon, and rectum) in Figs. 2, 3, 4, 5, 6. In fact, the better correlation
of PGE-MUM to the sum of eMayo than to the highest score of eMayo in pediatric patients with UC
was reported by Hagiwara et al (JPGN 2017). 
Analysis of correlation of PGE-MUM or FIT with histologic scores (histologic Matts score) may be
more attractive, if you have data. 
2.It can be also considered that eMayo 0 is defined as remission and eMayo 1 to 3 as active.
Could you check the difference of PGE-MUM or FIT between the group of eMayo 0 and the group of 1
to 3 in Fig. 6?
3.There  are  some  problems  regarding  the  significance  on  correlation  analysis  between  two
factors. I believe that r 0.5 is significant. 0.4< r <0.5 might be considered weak correlation. Would you ≧
ask a specialist of statistics to check statistical analysis?
Minor comments
1.Page 5, line 4. Ref 9 is the review article. Please use the original article (Arai Y ,  et al. J
Inflamm Bowel Dis 2014; 20: 1208) 
2.Page  7,  line  10.  Authors  wrote  that  urine  samples  were  obtained  on  the  morning  of  the
endoscopic examination. 
Didn't authors use pretreatment of endoscopy like laxative administration one day before endoscopy
which gives some influence to values of PGE-MUM? (Fujiwara M, et al. Digestion 2000; 61: 201) 
3.Description of Results is rather redundant. Please make them simple.
4.Page 12, line 41. Ref 10 is misleading.
5.Page 14, line 16, 26. PEG-MUM should be PGE-MUM
6.I recommend to authors adding numbers of cases in each group in Figs.
Are the methods appropriate and well described?
If not, please specify 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.
Unable to assess
Are you able to assess any statistics in the manuscript or would you recommend an additional
statistical review?
If  an  additional  statistical  review  is  recommended,  please  specify  what  aspects  require  further
assessment in your comments to the editors.
I recommend additional statistical review
Quality of written English
Please indicate the quality of language in the manuscript:
Needs some language corrections before being published
Declaration of competing interests
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3. Do you hold or are you currently applying for any patents relating to the content of the
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5. Do you have any other financial competing interests?
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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 am one of members who have developed a method measuring PGE-MUM and keep its patent.
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