Review for 10.1186/s12876-018-0749-3 (2018)

Reviewer ’s report  
 
Title: Epidemiology of gastrointestinal symptoms in young and middle -aged Swiss adults:  
prevalences and comorbidities in a longitudinal population cohort over 28 years  
 
Version: 1 Date: 30 Nov 2017  
 
Reviewer: Steven R Blanke  
 
Reviewer's report:  
 
This m anuscript entitled  "Epidemiology of gastrointestinal symptoms in young and middle -aged 
Swiss adults: prevalences and comorbidities in a longitudinal population cohort over 28 years" 
evaluates the prevalence of subacute and chronic gastrointestinal symptom s and their 
associations with somatic and mental disorders in the general population.  
 
Strengths of the manuscript include the importance of the overall area of study, the large, 
longitudinal nature of the study, and, the design of the study to eliminate a ge differences as a 
variable.  
 
 
The data are largely consistent with other publications. The weaknesses and caveats of the study 
are largely acknowledged by the authors. The data are difficult to interpret in terms of causality, 
and thus it is difficult to assess the extent to which this manuscript advances the field.  
 
The cover letter implies that the current manuscript is a resubmission, but there is no indication 
about the disposition of the original reviews, as well as the changes that have been made in 
response to the original critiques.  
 
 
 
Are the me thods appropriate and well described?  
If not, please specify what 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.  
 
Unable to assess  
 
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 recommend additional statistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscr ipt: 
 
Acceptable  
 
 
 
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursemen ts, fees, funding, or salary from an  
organisation that may in any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation 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 any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an org anization 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 competing interests in relation to this paper?  
 
If you can answer no to all o f 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 to the open peer review policy of the journal. 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 on the websi te along with the authors'  
responses. I agree for my report to be made available under a n 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 name d report can be included as confidential comments  
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal