Title: Feasibility and repeatability of ultrasound-guided surface electroenterography to measure
colonic slow wave motility in healthy adults
Version: 1 Date: 12 Dec 2023
Reviewer's report:
Dear authors
This paper describes a technique for recording human colonic slow waves with surface
electrodes. The electrodes were positioned using ultrasound. You have also tested the
repeatability of the technique. It is a nice procedure.
I have a few questions.
1. One of the key aspects of your paper is to assess the repeatability of the results. The electrodes
were placed using ultrasound the first time and then ~2 weeks later the test was repeated with
the electrodes placed in the same location as in the first recording. To ensure the electrodes were
on the colon in all locations, why wasn’t the ultra sound used for the second recording? Long
lengths of the colon are not fixed,  the second electrode placement may have been just off or
completely off the colon. By not using the same placement protocol for the 2 recordings can you
really say you have assessed the repeatability of the recordings? Had you used the ultrasound
the second time, you would have been able to address whether or not the regions of the colon
where in the same anatomical location within in the body. Given the electrodes must be close to
colon to get an accurate recording, reasonably precise placement is essential isn’t it?
2. The transverse colon and sigmoid colon often overlay part of the descending colon. In adults
and children with constipation, the sigmoid colon can sit behind or over the ascending, transverse
or sigmoid colon. How does ultrasound distinguish between these overlapping regions?
3. While the reproducibility of the results was statistically poor, it appears the results diffed
by only 0.5cpm. As you have stated in the paper the colonic slow wave frequency is between
2-6cpm. Therefore is there any clinical relevance at all in a difference of 0.5cpm. Both the first
and second recordings  appear to fall well within the normal range.
4. Based upon this slight difference in repeatability findings you also suggest, at line 210-11,
that “the low repeatability limits the usability of the studied measurement protocol for adequate
assessment of colonic motility”. Why do you say this? Again do you have any evidence to
suggest that a difference of 0.5cpm makes any difference to the measurements of colonic
motility? I would suggest the differences fall well within an acceptable margin of error.
5. Manometric studies, show that nearly all patient groups display dominant 2-6cpm activity
in the colon and that this activity increases after a meal. Therefore I wonder how you see this
technique being used in a clinical setting? If it can only detect the presence of slow wave
activity, what can it add to the diagnosis? Using your system, a healthy adult would likely have
a recordings very similar to a patient with IBS. Some discussion of what this technique could
add to diagnostics could be added.
Title: Feasibility and repeatability of ultrasound-guided surface electroenterography to measure
colonic slow wave motility in healthy adults
Version: 1 Date: 12 Dec 2023
Reviewer's report:
Dear authors
This paper describes a technique for recording human colonic slow waves with surface
electrodes. The electrodes were positioned using ultrasound. You have also tested the
repeatability of the technique. It is a nice procedure.
I have a few questions.
1. One of the key aspects of your paper is to assess the repeatability of the results. The electrodes
were placed using ultrasound the first time and then ~2 weeks later the test was repeated with
the electrodes placed in the same location as in the first recording. To ensure the electrodes were
on the colon in all locations, why wasn’t the ultra sound used for the second recording? Long
lengths of the colon are not fixed,  the second electrode placement may have been just off or
completely off the colon. By not using the same placement protocol for the 2 recordings can you
really say you have assessed the repeatability of the recordings? Had you used the ultrasound
the second time, you would have been able to address whether or not the regions of the colon
where in the same anatomical location within in the body. Given the electrodes must be close to
colon to get an accurate recording, reasonably precise placement is essential isn’t it?
2. The transverse colon and sigmoid colon often overlay part of the descending colon. In adults
and children with constipation, the sigmoid colon can sit behind or over the ascending, transverse
or sigmoid colon. How does ultrasound distinguish between these overlapping regions?
3. While the reproducibility of the results was statistically poor, it appears the results diffed
by only 0.5cpm. As you have stated in the paper the colonic slow wave frequency is between
2-6cpm. Therefore is there any clinical relevance at all in a difference of 0.5cpm. Both the first
and second recordings  appear to fall well within the normal range.
4. Based upon this slight difference in repeatability findings you also suggest, at line 210-11,
that “the low repeatability limits the usability of the studied measurement protocol for adequate
assessment of colonic motility”. Why do you say this? Again do you have any evidence to
suggest that a difference of 0.5cpm makes any difference to the measurements of colonic
motility? I would suggest the differences fall well within an acceptable margin of error.
5. Manometric studies, show that nearly all patient groups display dominant 2-6cpm activity
in the colon and that this activity increases after a meal. Therefore I wonder how you see this
technique being used in a clinical setting? If it can only detect the presence of slow wave
activity, what can it add to the diagnosis? Using your system, a healthy adult would likely have
a recordings very similar to a patient with IBS. Some discussion of what this technique could
add to diagnostics could be added.
Please review this paper.
user
Title: Feasibility and repeatability of ultrasound-guided surface electroenterography to measure
colonic slow wave motility in healthy adults
Version: 1 Date: 12 Dec 2023
Reviewer's report:
Dear authors
This paper describes a technique for recording human colonic slow waves with surface
electrodes. The electrodes were positioned using ultrasound. You have also tested the
repeatability of the technique. It is a nice procedure.
I have a few questions.
1. One of the key aspects of your paper is to assess the repeatability of the results. The electrodes
were placed using ultrasound the first time and then ~2 weeks later the test was repeated with
the electrodes placed in the same location as in the first recording. To ensure the electrodes were
on the colon in all locations, why wasn’t the ultra sound used for the second recording? Long
lengths of the colon are not fixed,  the second electrode placement may have been just off or
completely off the colon. By not using the same placement protocol for the 2 recordings can you
really say you have assessed the repeatability of the recordings? Had you used the ultrasound
the second time, you would have been able to address whether or not the regions of the colon
where in the same anatomical location within in the body. Given the electrodes must be close to
colon to get an accurate recording, reasonably precise placement is essential isn’t it?
2. The transverse colon and sigmoid colon often overlay part of the descending colon. In adults
and children with constipation, the sigmoid colon can sit behind or over the ascending, transverse
or sigmoid colon. How does ultrasound distinguish between these overlapping regions?
3. While the reproducibility of the results was statistically poor, it appears the results diffed
by only 0.5cpm. As you have stated in the paper the colonic slow wave frequency is between
2-6cpm. Therefore is there any clinical relevance at all in a difference of 0.5cpm. Both the first
and second recordings  appear to fall well within the normal range.
4. Based upon this slight difference in repeatability findings you also suggest, at line 210-11,
that “the low repeatability limits the usability of the studied measurement protocol for adequate
assessment of colonic motility”. Why do you say this? Again do you have any evidence to
suggest that a difference of 0.5cpm makes any difference to the measurements of colonic
motility? I would suggest the differences fall well within an acceptable margin of error.
5. Manometric studies, show that nearly all patient groups display dominant 2-6cpm activity
in the colon and that this activity increases after a meal. Therefore I wonder how you see this
technique being used in a clinical setting? If it can only detect the presence of slow wave
activity, what can it add to the diagnosis? Using your system, a healthy adult would likely have
a recordings very similar to a patient with IBS. Some discussion of what this technique could
add to diagnostics could be added.
assistant