Title: Multicenter epidemiological survey of pneumatosis intestinalis in Japan
Version: 2 Date: 27 Mar 2022
Reviewer's report:
I would like to thank the authors for the preparation of this excellent manuscript. The comments
to the manuscript are as follows:
Introduction:
1. (Line 114): Given that the authors discuss mortality as a result of PI, consider simply saying
that the pathology ranges from benign to death.
2. (Line  122): The type of PI and pathogenicity is thought to be related, and it may help elaborate
on this section just briefly (explaining primary and secondary PI)
Methods
3. (Line  163): The authors discuss dividing PI into large and small bowel types which is
essentially primary and secondary PI (see comment 2 above). Again, explaining the rationale
behind this separation in the introduction may help readers understand the rationale for the
method sections
Discussion
4. (Line 287):  This paragraph links bowel ischemia with death in PI, however,  based on the
author's data it is unclear if the 8 cases or mortality were linked to mesenteric ischemia. Was
the survey the author used able to determine if the complications used to define complicated PI
(especially in the 8 cases of mortality) all  linked to mesenteric ischemia?
Title: Multicenter epidemiological survey of pneumatosis intestinalis in Japan
Version: 2 Date: 27 Mar 2022
Reviewer's report:
I would like to thank the authors for the preparation of this excellent manuscript. The comments
to the manuscript are as follows:
Introduction:
1. (Line 114): Given that the authors discuss mortality as a result of PI, consider simply saying
that the pathology ranges from benign to death.
2. (Line  122): The type of PI and pathogenicity is thought to be related, and it may help elaborate
on this section just briefly (explaining primary and secondary PI)
Methods
3. (Line  163): The authors discuss dividing PI into large and small bowel types which is
essentially primary and secondary PI (see comment 2 above). Again, explaining the rationale
behind this separation in the introduction may help readers understand the rationale for the
method sections
Discussion
4. (Line 287):  This paragraph links bowel ischemia with death in PI, however,  based on the
author's data it is unclear if the 8 cases or mortality were linked to mesenteric ischemia. Was
the survey the author used able to determine if the complications used to define complicated PI
(especially in the 8 cases of mortality) all  linked to mesenteric ischemia?
Please review this paper.
user
Title: Multicenter epidemiological survey of pneumatosis intestinalis in Japan
Version: 2 Date: 27 Mar 2022
Reviewer's report:
I would like to thank the authors for the preparation of this excellent manuscript. The comments
to the manuscript are as follows:
Introduction:
1. (Line 114): Given that the authors discuss mortality as a result of PI, consider simply saying
that the pathology ranges from benign to death.
2. (Line  122): The type of PI and pathogenicity is thought to be related, and it may help elaborate
on this section just briefly (explaining primary and secondary PI)
Methods
3. (Line  163): The authors discuss dividing PI into large and small bowel types which is
essentially primary and secondary PI (see comment 2 above). Again, explaining the rationale
behind this separation in the introduction may help readers understand the rationale for the
method sections
Discussion
4. (Line 287):  This paragraph links bowel ischemia with death in PI, however,  based on the
author's data it is unclear if the 8 cases or mortality were linked to mesenteric ischemia. Was
the survey the author used able to determine if the complications used to define complicated PI
(especially in the 8 cases of mortality) all  linked to mesenteric ischemia?
assistant