Reviewer ’s report  
 
Title: Group cognitive behavioural therapy (GCBT) versus treatment as usual (TAU) in the 
treatment of irritable bowel syndrome (IBS): a study protocol for a randomized contro lled trial  
 
Version: 0 Date: 08 May 2019  
 
Reviewer: Sarah Ballou  
 
Reviewer's report:  
 
This manus cript "Group cognitive behavioral therapy (GCBT) versus treatment as usual (TAU) 
in the treatment of irritable bowel syndrome (IBS): a study protocol for a randomized controlled 
trial" describes the study protocol for a two -armed, parallel group, open labe l superiority trial 
evaluating group cognitive behavioral therapy against a waitlist control.  
 
This study will be a valuable addition to the literature and the publication of its protocol will be 
helpful for many researchers.  
 
 
My specific comments are as follows:  
 
1) In the abstract, the authors write that the results of this study will "clarify the relationship 
between IBS and psychological stress and will help to elucidate the underlying 
mechanisms of IBS". Please clarify how this study will accomplish th ese things.  
 
2) The authors mention that there are three RCTS of GCBT for IBS, with mixed findings. It 
would be very helpful if the authors dedicated a paragraph or two of the introduction 
and/or discussion to describing those studies, their findings, and h ow/why the current 
study will add to those previous trials.  
 
3) Why does this study use Rome III OR Rome IV criterai? Why not choose one? Please 
address this decision  
 
4) The decision to exclude patients who have had current or past psychotherapy is 
interest ing and warrants some discussion. Why was this decision made? Certainly, 
excluding these patients will make the sample much less representative of the IBS 
population.  
 
5) The authors describe the main components of the treatment (points a through g). If 
possible, it would be helpful to see how these components are allocated to each week. In 
other words, the protocol for GCBT treatment could be described with more clarity so 
that the reader can have a sense of what the treatment involves.  
 
6) The description of the GCBT therapists raises some questions. First, can a 
gastroenterologist really be considered a CBT therapist after having received 24 hours of 
supervised training? Second, why is a 'senior' psychologist with fewer years of clinical 
experience than th e second GCBT therapist providing supervision? Is that person trained 
in psychogastroenterology? Also, what does it mean that "subsequent" sessions will be 
supervised?  
 
7) The discussion is very short. Here, the authors might discuss how this study will add  to 
the existing literature. Again, it would be helpful for the authors to discuss the group cbt 
research that has already been done in IBS. Why do the authors think that there have been 
conflicting results? Differences in methodologies of the studies? Som ething about the 
patient population or the nature of IBS?  
 
8) It would also be worth mentioning in the introduction or discussion that this study uses a 
CBT approach that is modeled after treatment for panic disorder. This approach has been 
tested and show n to be effective for IBS. Interoceptive management for IBS is innovative 
and has a strong theoretical background for use in IBS, but there are some differences in 
this CBT approach vs. the more common or 'traditional' CBT for IBS. For example, the 
most no table differences seem to be the inclusion of point 'e', exposure to visceral 
sensations, as well as the absence of relaxation training. The authors might consider 
describing these differences and why their treatment protocol might be more suited to 
GCBT.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
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 the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
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 speci fy 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  
Please complete a declaration of competing interests, considering the following questions:  
 
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 receiv ed 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 competing interests i n 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 to 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 websi te 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 name d report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title: Group cognitive behavioural therapy (GCBT) versus treatment as usual (TAU) in the 
treatment of irritable bowel syndrome (IBS): a study protocol for a randomized contro lled trial  
 
Version: 0 Date: 08 May 2019  
 
Reviewer: Sarah Ballou  
 
Reviewer's report:  
 
This manus cript "Group cognitive behavioral therapy (GCBT) versus treatment as usual (TAU) 
in the treatment of irritable bowel syndrome (IBS): a study protocol for a randomized controlled 
trial" describes the study protocol for a two -armed, parallel group, open labe l superiority trial 
evaluating group cognitive behavioral therapy against a waitlist control.  
 
This study will be a valuable addition to the literature and the publication of its protocol will be 
helpful for many researchers.  
 
 
My specific comments are as follows:  
 
1) In the abstract, the authors write that the results of this study will "clarify the relationship 
between IBS and psychological stress and will help to elucidate the underlying 
mechanisms of IBS". Please clarify how this study will accomplish th ese things.  
 
2) The authors mention that there are three RCTS of GCBT for IBS, with mixed findings. It 
would be very helpful if the authors dedicated a paragraph or two of the introduction 
and/or discussion to describing those studies, their findings, and h ow/why the current 
study will add to those previous trials.  
 
3) Why does this study use Rome III OR Rome IV criterai? Why not choose one? Please 
address this decision  
 
4) The decision to exclude patients who have had current or past psychotherapy is 
interest ing and warrants some discussion. Why was this decision made? Certainly, 
excluding these patients will make the sample much less representative of the IBS 
population.  
 
5) The authors describe the main components of the treatment (points a through g). If 
possible, it would be helpful to see how these components are allocated to each week. In 
other words, the protocol for GCBT treatment could be described with more clarity so 
that the reader can have a sense of what the treatment involves.  
 
6) The description of the GCBT therapists raises some questions. First, can a 
gastroenterologist really be considered a CBT therapist after having received 24 hours of 
supervised training? Second, why is a 'senior' psychologist with fewer years of clinical 
experience than th e second GCBT therapist providing supervision? Is that person trained 
in psychogastroenterology? Also, what does it mean that "subsequent" sessions will be 
supervised?  
 
7) The discussion is very short. Here, the authors might discuss how this study will add  to 
the existing literature. Again, it would be helpful for the authors to discuss the group cbt 
research that has already been done in IBS. Why do the authors think that there have been 
conflicting results? Differences in methodologies of the studies? Som ething about the 
patient population or the nature of IBS?  
 
8) It would also be worth mentioning in the introduction or discussion that this study uses a 
CBT approach that is modeled after treatment for panic disorder. This approach has been 
tested and show n to be effective for IBS. Interoceptive management for IBS is innovative 
and has a strong theoretical background for use in IBS, but there are some differences in 
this CBT approach vs. the more common or 'traditional' CBT for IBS. For example, the 
most no table differences seem to be the inclusion of point 'e', exposure to visceral 
sensations, as well as the absence of relaxation training. The authors might consider 
describing these differences and why their treatment protocol might be more suited to 
GCBT.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
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 the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
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 speci fy 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  
Please complete a declaration of competing interests, considering the following questions:  
 
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 receiv ed 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 competing interests i n 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 to 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 websi te 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 name d report can be in cluded as confidential comments 
to the editors, 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: Group cognitive behavioural therapy (GCBT) versus treatment as usual (TAU) in the 
treatment of irritable bowel syndrome (IBS): a study protocol for a randomized contro lled trial  
 
Version: 0 Date: 08 May 2019  
 
Reviewer: Sarah Ballou  
 
Reviewer's report:  
 
This manus cript "Group cognitive behavioral therapy (GCBT) versus treatment as usual (TAU) 
in the treatment of irritable bowel syndrome (IBS): a study protocol for a randomized controlled 
trial" describes the study protocol for a two -armed, parallel group, open labe l superiority trial 
evaluating group cognitive behavioral therapy against a waitlist control.  
 
This study will be a valuable addition to the literature and the publication of its protocol will be 
helpful for many researchers.  
 
 
My specific comments are as follows:  
 
1) In the abstract, the authors write that the results of this study will "clarify the relationship 
between IBS and psychological stress and will help to elucidate the underlying 
mechanisms of IBS". Please clarify how this study will accomplish th ese things.  
 
2) The authors mention that there are three RCTS of GCBT for IBS, with mixed findings. It 
would be very helpful if the authors dedicated a paragraph or two of the introduction 
and/or discussion to describing those studies, their findings, and h ow/why the current 
study will add to those previous trials.  
 
3) Why does this study use Rome III OR Rome IV criterai? Why not choose one? Please 
address this decision  
 
4) The decision to exclude patients who have had current or past psychotherapy is 
interest ing and warrants some discussion. Why was this decision made? Certainly, 
excluding these patients will make the sample much less representative of the IBS 
population.  
 
5) The authors describe the main components of the treatment (points a through g). If 
possible, it would be helpful to see how these components are allocated to each week. In 
other words, the protocol for GCBT treatment could be described with more clarity so 
that the reader can have a sense of what the treatment involves.  
 
6) The description of the GCBT therapists raises some questions. First, can a 
gastroenterologist really be considered a CBT therapist after having received 24 hours of 
supervised training? Second, why is a 'senior' psychologist with fewer years of clinical 
experience than th e second GCBT therapist providing supervision? Is that person trained 
in psychogastroenterology? Also, what does it mean that "subsequent" sessions will be 
supervised?  
 
7) The discussion is very short. Here, the authors might discuss how this study will add  to 
the existing literature. Again, it would be helpful for the authors to discuss the group cbt 
research that has already been done in IBS. Why do the authors think that there have been 
conflicting results? Differences in methodologies of the studies? Som ething about the 
patient population or the nature of IBS?  
 
8) It would also be worth mentioning in the introduction or discussion that this study uses a 
CBT approach that is modeled after treatment for panic disorder. This approach has been 
tested and show n to be effective for IBS. Interoceptive management for IBS is innovative 
and has a strong theoretical background for use in IBS, but there are some differences in 
this CBT approach vs. the more common or 'traditional' CBT for IBS. For example, the 
most no table differences seem to be the inclusion of point 'e', exposure to visceral 
sensations, as well as the absence of relaxation training. The authors might consider 
describing these differences and why their treatment protocol might be more suited to 
GCBT.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
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 the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
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 speci fy 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  
Please complete a declaration of competing interests, considering the following questions:  
 
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 receiv ed 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 competing interests i n 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 to 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 websi te 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 name d report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
assistant