Review for 10.1186/s12876-019-1103-0 (2019)

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:  
 
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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  
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