Review for 10.1186/s12876-020-01301-3 (2020)

Reviewer ’s report  
 
Title: Ischemic colitis induced by indigo naturalis in a patient with ulcerative colitis: A case 
report  
 
Version: 0 Date: 23 Apr 2020  
 
Reviewer: Peter Thelin Schmidt  
 
Reviewer's report:  
 
The case report describes a case of suspected ischemic colitis after intake of indigo naturalis.  
The repost is well written and ads to the literature on adverse events related to indigo 
naturalis.  
 
Minor points:  
Page 3 , line 30 -31. Describe the previous extension of her UC.  
Page 3, line 42,43. How often did she ingest indigo naturalis and in what amounts?  
Page 3, line 48 -51, include the reference interval for white blood cell count, Hb and CRP.  
Page 3, line 54 -57 and f ig 1. The resolution is quite low, and it is hard to see coloring from 
indigo naturalis (in contrast to Fig 4b).  
Page 4, line 42. Include the number of patients in the "relatively small study".  
Page 5, 17 -18. Confusing that patient with ulcerative colitis developed colitis. Another kind 
of colitis than UC or flares of UC?  
The CARE check list, point 12. I can not find the patients perspective that according to the 
checklist is reported on page 4, paragraph 2.     
 
 
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 necess ary 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.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
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 
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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 r elation to this paper?  
 
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below.  If your reply is yes to any, please give details below.  
 
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