Reviewer’s report 
Title:  A case report of sevelamer-associated recto-sigmoi d ulcers. 
 
Version:  0 Date:  10 Nov 2015 
 
Reviewer:  Dora Lam-Himlin 
 
Reviewer's report: 
This is a nice case report of the finding of sevela mer resin associated with rectal ulcers occurring 
in a symptomatic patient. Due to the sparse literat ure on this topic, it is unclear whether 
sevelamer causes mucosal injury, or is simply found  in association with underlying conditions. 
This case does not clarify the issue, but does add to our knowledge base of the medication resin. 
A few points require clarification and can strength en this case report. 
 
1. The authors refrain from concluding that the ulc ers were caused by the sevelamer.  Given 
the current evidence, this seems appropriate.  Howe ver, in the discussion, it may be useful 
for the authors to speculate whether they feel the resinous material was incidentally adherent 
to the mucosa as a result of an underlying disease process (?IBD, chronic C. diff infection, 
acute CMV infection, or other reason for rectal ulc ers) and therefore non-etiologic.  Or, 
since the C. diff appears to have been cleared, whe ther the authors authors feel this resinous 
material was the primary cause for the rectal ulcer s.   
 
2. Were the crystals embedded in the tissue, mixed within the fibroinflammatory debris, 
adherent to the lumenal surface, or found in lumina l areas without tissue reaction? 
 
3. Though few in number, the cases reported by Swan son et al. implicated a dose-dependent 
relationship between the medication and mucosal inj ury.  State the dosage for this patient. 
 
4. Clinical follow-up was provided following cessat ion of the medication, but no commentary 
was provided on repeat endoscopy.  The results of a ny follow-up endoscopy and biopsies 
would make this a much stronger case report. I susp ect follow-up sigmoidoscopy would be 
desired for patient care, regardless. 
 
Are the methods appropriate and well described? 
If not, please specify what is required in your com ments 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 t he data shown? 
If not, please explain in your comments to the auth ors. 
Yes 
Are you able to assess any statistics in the manusc ript 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 manu script: 
Acceptable 
Declaration of competing interests 
Please complete a declaration of competing interest s, considering the following questions: 
1. Have you in the past five years received reimbur sements, fees, funding, or salary from an 
organisation that may in any way gain or lose finan cially from the publication of this 
manuscript, either now or in the future? 
2. Do you hold any stocks or shares in an organisat ion that 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 an y 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 intere sts? 
6. Do you have any non-financial competing interest s 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 det ails below. 
I declare that I have no competing interests. 
I agree to the open peer review policy of the journ al. I understand that my name will be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted o n the website along with the authors' 
responses. I agree for my report to be made availab le 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 repo rt can be included as confidential comments 
to the editors, which will not be published. 
I agree to the open peer review policy of the journ al 
Reviewer’s report 
Title:  A case report of sevelamer-associated recto-sigmoi d ulcers. 
 
Version:  0 Date:  10 Nov 2015 
 
Reviewer:  Dora Lam-Himlin 
 
Reviewer's report: 
This is a nice case report of the finding of sevela mer resin associated with rectal ulcers occurring 
in a symptomatic patient. Due to the sparse literat ure on this topic, it is unclear whether 
sevelamer causes mucosal injury, or is simply found  in association with underlying conditions. 
This case does not clarify the issue, but does add to our knowledge base of the medication resin. 
A few points require clarification and can strength en this case report. 
 
1. The authors refrain from concluding that the ulc ers were caused by the sevelamer.  Given 
the current evidence, this seems appropriate.  Howe ver, in the discussion, it may be useful 
for the authors to speculate whether they feel the resinous material was incidentally adherent 
to the mucosa as a result of an underlying disease process (?IBD, chronic C. diff infection, 
acute CMV infection, or other reason for rectal ulc ers) and therefore non-etiologic.  Or, 
since the C. diff appears to have been cleared, whe ther the authors authors feel this resinous 
material was the primary cause for the rectal ulcer s.   
 
2. Were the crystals embedded in the tissue, mixed within the fibroinflammatory debris, 
adherent to the lumenal surface, or found in lumina l areas without tissue reaction? 
 
3. Though few in number, the cases reported by Swan son et al. implicated a dose-dependent 
relationship between the medication and mucosal inj ury.  State the dosage for this patient. 
 
4. Clinical follow-up was provided following cessat ion of the medication, but no commentary 
was provided on repeat endoscopy.  The results of a ny follow-up endoscopy and biopsies 
would make this a much stronger case report. I susp ect follow-up sigmoidoscopy would be 
desired for patient care, regardless. 
 
Are the methods appropriate and well described? 
If not, please specify what is required in your com ments 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 t he data shown? 
If not, please explain in your comments to the auth ors. 
Yes 
Are you able to assess any statistics in the manusc ript 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 manu script: 
Acceptable 
Declaration of competing interests 
Please complete a declaration of competing interest s, considering the following questions: 
1. Have you in the past five years received reimbur sements, fees, funding, or salary from an 
organisation that may in any way gain or lose finan cially from the publication of this 
manuscript, either now or in the future? 
2. Do you hold any stocks or shares in an organisat ion that 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 an y 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 intere sts? 
6. Do you have any non-financial competing interest s 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 det ails below. 
I declare that I have no competing interests. 
I agree to the open peer review policy of the journ al. I understand that my name will be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted o n the website along with the authors' 
responses. I agree for my report to be made availab le 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 repo rt can be included as confidential comments 
to the editors, which will not be published. 
I agree to the open peer review policy of the journ al 
Please review this paper.
user
Reviewer’s report 
Title:  A case report of sevelamer-associated recto-sigmoi d ulcers. 
 
Version:  0 Date:  10 Nov 2015 
 
Reviewer:  Dora Lam-Himlin 
 
Reviewer's report: 
This is a nice case report of the finding of sevela mer resin associated with rectal ulcers occurring 
in a symptomatic patient. Due to the sparse literat ure on this topic, it is unclear whether 
sevelamer causes mucosal injury, or is simply found  in association with underlying conditions. 
This case does not clarify the issue, but does add to our knowledge base of the medication resin. 
A few points require clarification and can strength en this case report. 
 
1. The authors refrain from concluding that the ulc ers were caused by the sevelamer.  Given 
the current evidence, this seems appropriate.  Howe ver, in the discussion, it may be useful 
for the authors to speculate whether they feel the resinous material was incidentally adherent 
to the mucosa as a result of an underlying disease process (?IBD, chronic C. diff infection, 
acute CMV infection, or other reason for rectal ulc ers) and therefore non-etiologic.  Or, 
since the C. diff appears to have been cleared, whe ther the authors authors feel this resinous 
material was the primary cause for the rectal ulcer s.   
 
2. Were the crystals embedded in the tissue, mixed within the fibroinflammatory debris, 
adherent to the lumenal surface, or found in lumina l areas without tissue reaction? 
 
3. Though few in number, the cases reported by Swan son et al. implicated a dose-dependent 
relationship between the medication and mucosal inj ury.  State the dosage for this patient. 
 
4. Clinical follow-up was provided following cessat ion of the medication, but no commentary 
was provided on repeat endoscopy.  The results of a ny follow-up endoscopy and biopsies 
would make this a much stronger case report. I susp ect follow-up sigmoidoscopy would be 
desired for patient care, regardless. 
 
Are the methods appropriate and well described? 
If not, please specify what is required in your com ments 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 t he data shown? 
If not, please explain in your comments to the auth ors. 
Yes 
Are you able to assess any statistics in the manusc ript 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 manu script: 
Acceptable 
Declaration of competing interests 
Please complete a declaration of competing interest s, considering the following questions: 
1. Have you in the past five years received reimbur sements, fees, funding, or salary from an 
organisation that may in any way gain or lose finan cially from the publication of this 
manuscript, either now or in the future? 
2. Do you hold any stocks or shares in an organisat ion that 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 an y 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 intere sts? 
6. Do you have any non-financial competing interest s 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 det ails below. 
I declare that I have no competing interests. 
I agree to the open peer review policy of the journ al. I understand that my name will be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted o n the website along with the authors' 
responses. I agree for my report to be made availab le 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 repo rt can be included as confidential comments 
to the editors, which will not be published. 
I agree to the open peer review policy of the journ al 
assistant