Title: Multicenter epidemiological survey of pneumatosis intestinalis in Japan
Version: 3 Date: 24 Apr 2022
Reviewer's report:
I would first like to thank the authors for their dedication and hard work in creating and editing
this manuscript. My comments are as follows:
Introduction: The introduction section could be more consistently arranged. In its current form,
the authors discuss what PI is, where it is found, prognosis, mechanism, prognosis (again),
classification, and mechanism (again).  This should be arranged in a manner that flows: what is
PI, review the classification system (which includes the proposed mechanisms), and then discuss
prognosis and why this paper is important to help us further understand how to prognosticate
cases where PI is discovered.
- Line 112: Consider rewording “benign outcome” as this could mean that with aggressive
treatment there was no increased mortality or (and what is more likely) the authors mean that
PI spontaneously resolves. For example: the clinical significance of PI varies from an incidental
finding that resolves spontaneously to death.
Patients and Methods: overall, this section is well done. I think it may be beneficial to define
chronic kidney disease given that it is one of the key findings in this paper. If the stage is
unknown (if this data was generated by selecting CKD on the questionnaire), then I would
include that fact in the discussion on limitations because there could potentially be a significant
difference in patients with CKD stage 2 vs 5 (which the authors later allude to in line 262). In
a similar sense, grouping all “laxatives” as one may be confounding, as lactulose has been well
implicated in causing PI, whereas most other laxatives have not.
Discussion: Again, an overall well-done section. I think the limitations section could probably
be elaborated on. Especially as above (in regards to CKD).
- Line 238: If you alter the beginning of the sentence “A prospective multicenter study…” to
include “These results support the findings of another prospective multicenter study…” it would
help the reader easily understand the importance of this study in relationship to the others. This
is done later in the paragraph, but there is some initial confusion at the abrupt transition.
Title: Multicenter epidemiological survey of pneumatosis intestinalis in Japan
Version: 3 Date: 24 Apr 2022
Reviewer's report:
I would first like to thank the authors for their dedication and hard work in creating and editing
this manuscript. My comments are as follows:
Introduction: The introduction section could be more consistently arranged. In its current form,
the authors discuss what PI is, where it is found, prognosis, mechanism, prognosis (again),
classification, and mechanism (again).  This should be arranged in a manner that flows: what is
PI, review the classification system (which includes the proposed mechanisms), and then discuss
prognosis and why this paper is important to help us further understand how to prognosticate
cases where PI is discovered.
- Line 112: Consider rewording “benign outcome” as this could mean that with aggressive
treatment there was no increased mortality or (and what is more likely) the authors mean that
PI spontaneously resolves. For example: the clinical significance of PI varies from an incidental
finding that resolves spontaneously to death.
Patients and Methods: overall, this section is well done. I think it may be beneficial to define
chronic kidney disease given that it is one of the key findings in this paper. If the stage is
unknown (if this data was generated by selecting CKD on the questionnaire), then I would
include that fact in the discussion on limitations because there could potentially be a significant
difference in patients with CKD stage 2 vs 5 (which the authors later allude to in line 262). In
a similar sense, grouping all “laxatives” as one may be confounding, as lactulose has been well
implicated in causing PI, whereas most other laxatives have not.
Discussion: Again, an overall well-done section. I think the limitations section could probably
be elaborated on. Especially as above (in regards to CKD).
- Line 238: If you alter the beginning of the sentence “A prospective multicenter study…” to
include “These results support the findings of another prospective multicenter study…” it would
help the reader easily understand the importance of this study in relationship to the others. This
is done later in the paragraph, but there is some initial confusion at the abrupt transition.
Please review this paper.
user
Title: Multicenter epidemiological survey of pneumatosis intestinalis in Japan
Version: 3 Date: 24 Apr 2022
Reviewer's report:
I would first like to thank the authors for their dedication and hard work in creating and editing
this manuscript. My comments are as follows:
Introduction: The introduction section could be more consistently arranged. In its current form,
the authors discuss what PI is, where it is found, prognosis, mechanism, prognosis (again),
classification, and mechanism (again).  This should be arranged in a manner that flows: what is
PI, review the classification system (which includes the proposed mechanisms), and then discuss
prognosis and why this paper is important to help us further understand how to prognosticate
cases where PI is discovered.
- Line 112: Consider rewording “benign outcome” as this could mean that with aggressive
treatment there was no increased mortality or (and what is more likely) the authors mean that
PI spontaneously resolves. For example: the clinical significance of PI varies from an incidental
finding that resolves spontaneously to death.
Patients and Methods: overall, this section is well done. I think it may be beneficial to define
chronic kidney disease given that it is one of the key findings in this paper. If the stage is
unknown (if this data was generated by selecting CKD on the questionnaire), then I would
include that fact in the discussion on limitations because there could potentially be a significant
difference in patients with CKD stage 2 vs 5 (which the authors later allude to in line 262). In
a similar sense, grouping all “laxatives” as one may be confounding, as lactulose has been well
implicated in causing PI, whereas most other laxatives have not.
Discussion: Again, an overall well-done section. I think the limitations section could probably
be elaborated on. Especially as above (in regards to CKD).
- Line 238: If you alter the beginning of the sentence “A prospective multicenter study…” to
include “These results support the findings of another prospective multicenter study…” it would
help the reader easily understand the importance of this study in relationship to the others. This
is done later in the paragraph, but there is some initial confusion at the abrupt transition.
assistant