Review for 10.1186/s12876-021-01879-2 (2021)

Reviewer’s report
Title: 
Pain and psyche in a patient with irritable bowel syndrome—chicken or
egg? A time series case report
Version: 
0 
Date: 
12 Mar 2021
Reviewer's report:
POverall recommendation: revision 
Comments:
This was a single-case study used a longitudinal observational design over 72
days to investigate the temporal relationships of somatic symptoms (i.e.,
abdominal pain, daily impairment) with psychological symptoms (i.e.,
nervousness, tension, depressiveness, pain associated discomfort), and coping
strategies (i.e., catastrophizing, hopelessness, coping relative to positive thoughts
and imaging pain outside the body) through an autoregressive (VAR) modeling
approach. VAR results suggested that worse abdominal pain predicted worse
psychological symptoms on the following day, and an intensified use of positive
thinking as a positive coping strategy reduced the severity of abdominal pain on
the following day. This manuscript is generally well-written and has potential
contribution to the current literature. I have no major comments, but I have some
comments as below to clarify and improve the manuscript. 
Introduction:
1. Line 111-112: 
the second objective of this case study was "to investigate the
impact of personal coping strategies". Based on the what follows, does this mean
"to investigate the impact of personal coping strategies on somatic symptoms"?
Case presentations: 
2. Line 143: please clarify what's IBS subtype given this case. 
3. Line 127-135: the subheading here only mentioned psychological
measurements and the authors provided more details in Table 1. Actually, Table
1 included not only psychological variables, but also somatic and coping related
variables. Therefore, it could be confusing to the readers what items were really
included into these three categories of somatization, psychology and coping in
this manuscript. It would be better to briefly describe how the authors categorize
these items, and how to interpret the scores of these items. 
Results:
4. The bottom line of Table 2 was missed. Also please add the interpretations for
these item scores in the table legend.
5. Line 218-219: it could be better to revise the title of Table 3 as "significant
instantaneous correlations of somatization with psychological and coping
variables" to make consistent with the defined categories in Table 1.
6. Line 221-222: since the authors clearly included abdominal pain (AP) and
daily impairment (DI) as independent variables in the regressions, 
the authors
may consider the revise the regression equations as "PVt=
β
1APt+
β
2DIt" in the
legend of Table 3.
Discussion and conclusion: 
7. Line 289-295: the authors primarily disused the same-day correlations
between somatic (especially daily impairment) and psychological variables
(nervousness, tension, depressiveness, catastrophizing, hopelessness) in this case
study and then used the 21th reference to support it. However, actually this
reference was a review paper and discussed abdominal pain and psychological
distress only, but not included daily impairment in IBS. Therefore, it would be
great to find other research studies which examined the relationships among
abdominal pain, daily impairment and psychological distress in IBS to support
this finding. 
8. Line 305-309: the authors discussed the primary finding regarding a greater
severity of abdominal pain was associated with greater psychological distress on
the following day, not vice versa and then used the 24th reference to support it.
However, there were some studies showing the opposite direction of this
relationship: greater psychological distress was associated with a greater severity
of abdominal pain on the following day such as Patel et al 2016 "Effects of
disturbed sleep on gastrointestinal and somatic pain symptoms in irritable bowel
syndrome". There is a need to discuss. 
9. Line 331-333: there was very limited range of depressiveness over 72 days in
this case (min: 1, max: 30 SD: 4.42 on the scale of 1-101). Therefore, the authors
may need to consider if it caused no relationship between depressiveness and
somatic symptoms.
10. Overall, the authors used qualitative explanations to support the VAR
findings. It would be much greater to propose physiological mechanisms to
support these interesting VAR findings as well.
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
No
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, 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
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 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 i have no competing interests
Reviewer Publication Consent.
 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
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the
editorial office before completing the review.
If you wish, you can include your
name in your published report. Please note you must decide whether to include
your name at the start of the process and confirm this decision whenever
prompted. If you change your decision later, we will not be able to publish your
name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes