Reviewer ’s report  
 
Title: Irritable bowel syndrome -like symptoms and health related quality of life two years after  
Roux -en-Y gastric bypass - a prospective cohort study  
 
Version: 0 Date: 30 May 2019  
 
Reviewer: Cesare Cremon  
 
Reviewer's report:  
 
Please include all comments for the authors in this box rather than uploading your report as an 
attachment. Please only upload as attachments annotated versions of manuscripts, graphs, 
supporting materials or other aspects of your report which cannot be included in a text format.  
 
 
Please overwrite this text when adding your comments to the authors.  
 
 
This is an interesting prospective cohort study assessing the prevalence of irritable bowel 
syndrome (IBS) 2 years after intervention of Roux -en-Y gastric bypass (RYGB) for morbid 
obesity. The Authors showed that the prevalence of new IBS was 22% (45/206 pa tients) after 
RYGB with significant worsening of the mental component score of quality of life. In addition, 
preoperative IBS and fibromyalgia were associated with postoperative IBS.  
 
 
The study appears to be well designed and conducted, and the results ar e clearly reported. The 
discussion is consistent with the results. However, there are flaws that reduce the quality of the 
manuscript:  
 
 
RYGB may be considered as a predisposing factor for small intestinal bacterial overgrowth 
(SIBO), condition characterized by symptoms overlapping with IBS. Did the authors exclude 
SIBO in their patients after RYGB by glucose breath testing or culture of je junum aspirate for 
bacterial counts? Probably, a high proportion of subjects suffer of this condition rather than IBS. 
If the authors did not evaluate this aspect, I suggest to include this in discussion as a major 
limitation of the study.  
 
 
I suggest to pr efer the term IBS -like symptoms rather than IBS. By definition, IBS is a functional 
bowel disorder in which macroscopic organic causes are excluded. RYGB may perturb pain 
perception and alter gastrointestinal physiology, pathophysiological mechanisms invol ved in 
symptom generation in IBS.  
 
 
It is well defined that factors triggering the onset or exacerbation of IBS symptoms include for 
example surgery. The study is lacking of a control group represented for example by subjects 
who underwent laparoscopic cho lecystectomy. It is possible that laparoscopic abdominal 
surgery, rather than RYGB, is involved in new onset of IBS -like symptoms. I suggest to include 
a control group to assess the real prevalence of new IBS -like symptoms after RYGB.  
 
 
Typos  
 
Page 13, Line 39-44: These findings supports an association…. and highlights  
 
 
 
Are the methods appropriate and well described?  
If not, please specify w hat 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.  
 
No 
 
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 specify what aspects requir e 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  
 
 
 
 
 
 
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following quest ions:  
 
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 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 interests?  
 
6. Do you have any non -financial com peting 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 have no competing interests  
 
I agree t o the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available 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 report can be in cluded as confidential comments 
to the editor s, which will not be published.  
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title: Irritable bowel syndrome -like symptoms and health related quality of life two years after  
Roux -en-Y gastric bypass - a prospective cohort study  
 
Version: 0 Date: 30 May 2019  
 
Reviewer: Cesare Cremon  
 
Reviewer's report:  
 
Please include all comments for the authors in this box rather than uploading your report as an 
attachment. Please only upload as attachments annotated versions of manuscripts, graphs, 
supporting materials or other aspects of your report which cannot be included in a text format.  
 
 
Please overwrite this text when adding your comments to the authors.  
 
 
This is an interesting prospective cohort study assessing the prevalence of irritable bowel 
syndrome (IBS) 2 years after intervention of Roux -en-Y gastric bypass (RYGB) for morbid 
obesity. The Authors showed that the prevalence of new IBS was 22% (45/206 pa tients) after 
RYGB with significant worsening of the mental component score of quality of life. In addition, 
preoperative IBS and fibromyalgia were associated with postoperative IBS.  
 
 
The study appears to be well designed and conducted, and the results ar e clearly reported. The 
discussion is consistent with the results. However, there are flaws that reduce the quality of the 
manuscript:  
 
 
RYGB may be considered as a predisposing factor for small intestinal bacterial overgrowth 
(SIBO), condition characterized by symptoms overlapping with IBS. Did the authors exclude 
SIBO in their patients after RYGB by glucose breath testing or culture of je junum aspirate for 
bacterial counts? Probably, a high proportion of subjects suffer of this condition rather than IBS. 
If the authors did not evaluate this aspect, I suggest to include this in discussion as a major 
limitation of the study.  
 
 
I suggest to pr efer the term IBS -like symptoms rather than IBS. By definition, IBS is a functional 
bowel disorder in which macroscopic organic causes are excluded. RYGB may perturb pain 
perception and alter gastrointestinal physiology, pathophysiological mechanisms invol ved in 
symptom generation in IBS.  
 
 
It is well defined that factors triggering the onset or exacerbation of IBS symptoms include for 
example surgery. The study is lacking of a control group represented for example by subjects 
who underwent laparoscopic cho lecystectomy. It is possible that laparoscopic abdominal 
surgery, rather than RYGB, is involved in new onset of IBS -like symptoms. I suggest to include 
a control group to assess the real prevalence of new IBS -like symptoms after RYGB.  
 
 
Typos  
 
Page 13, Line 39-44: These findings supports an association…. and highlights  
 
 
 
Are the methods appropriate and well described?  
If not, please specify w hat 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.  
 
No 
 
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 specify what aspects requir e 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  
 
 
 
 
 
 
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following quest ions:  
 
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 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 interests?  
 
6. Do you have any non -financial com peting 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 have no competing interests  
 
I agree t o the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available 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 report can be in cluded as confidential comments 
to the editor s, which will not be published.  
 
I agree to the open peer review policy of the journal  
Please review this paper.
user
Reviewer ’s report  
 
Title: Irritable bowel syndrome -like symptoms and health related quality of life two years after  
Roux -en-Y gastric bypass - a prospective cohort study  
 
Version: 0 Date: 30 May 2019  
 
Reviewer: Cesare Cremon  
 
Reviewer's report:  
 
Please include all comments for the authors in this box rather than uploading your report as an 
attachment. Please only upload as attachments annotated versions of manuscripts, graphs, 
supporting materials or other aspects of your report which cannot be included in a text format.  
 
 
Please overwrite this text when adding your comments to the authors.  
 
 
This is an interesting prospective cohort study assessing the prevalence of irritable bowel 
syndrome (IBS) 2 years after intervention of Roux -en-Y gastric bypass (RYGB) for morbid 
obesity. The Authors showed that the prevalence of new IBS was 22% (45/206 pa tients) after 
RYGB with significant worsening of the mental component score of quality of life. In addition, 
preoperative IBS and fibromyalgia were associated with postoperative IBS.  
 
 
The study appears to be well designed and conducted, and the results ar e clearly reported. The 
discussion is consistent with the results. However, there are flaws that reduce the quality of the 
manuscript:  
 
 
RYGB may be considered as a predisposing factor for small intestinal bacterial overgrowth 
(SIBO), condition characterized by symptoms overlapping with IBS. Did the authors exclude 
SIBO in their patients after RYGB by glucose breath testing or culture of je junum aspirate for 
bacterial counts? Probably, a high proportion of subjects suffer of this condition rather than IBS. 
If the authors did not evaluate this aspect, I suggest to include this in discussion as a major 
limitation of the study.  
 
 
I suggest to pr efer the term IBS -like symptoms rather than IBS. By definition, IBS is a functional 
bowel disorder in which macroscopic organic causes are excluded. RYGB may perturb pain 
perception and alter gastrointestinal physiology, pathophysiological mechanisms invol ved in 
symptom generation in IBS.  
 
 
It is well defined that factors triggering the onset or exacerbation of IBS symptoms include for 
example surgery. The study is lacking of a control group represented for example by subjects 
who underwent laparoscopic cho lecystectomy. It is possible that laparoscopic abdominal 
surgery, rather than RYGB, is involved in new onset of IBS -like symptoms. I suggest to include 
a control group to assess the real prevalence of new IBS -like symptoms after RYGB.  
 
 
Typos  
 
Page 13, Line 39-44: These findings supports an association…. and highlights  
 
 
 
Are the methods appropriate and well described?  
If not, please specify w hat 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.  
 
No 
 
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 specify what aspects requir e 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  
 
 
 
 
 
 
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following quest ions:  
 
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 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 interests?  
 
6. Do you have any non -financial com peting 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 have no competing interests  
 
I agree t o the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available 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 report can be in cluded as confidential comments 
to the editor s, which will not be published.  
 
I agree to the open peer review policy of the journal  
assistant