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: 2 Date: 19 Jan 2020
Reviewer: Isao Okayasu
Reviewer's report:
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Most of questions were answered well. But a few points should be cleared, as follows.
Major points
1.Authors wrote "In this study, almost all the patients received laxative administration 
on the day before colonoscopy. Each time, urine and fecal specimens were collected." (page 6, line 3)
Were urine specimens obtained before or after laxative administration? 
PGE-MUM values on the base line (eMayo 0 score) in Fig 2A were relatively higher than those
published in the previous report (Arai et al, Inflamm Bowel Dis 2014)
I wonder if laxative administration gave any influence on PGE-MUM values.
About this point, please explain and describe accurately.
2.PGE-MUM is thought to reflect inflammatory condition of the whole colon. Again, the sum of
eMayo scores might be more comparable than eMayo in Figs 4, 5. Could you try to see it?
Minor point
1.Authors wrote "Conclusions: PGE-MUM is as useful a biomarker as FIT..." (page 3, line 51)
   "Conclusions: PGE-MUM is useful as a biomarker as FIT..." is correct.
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 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 am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
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