Review for 10.1186/s12876-023-02861-w (2023)

Title: Associations and gastrointestinal symptoms in women with endometriosis in comparison
to women with irritable bowel syndrome: A  study based on a population cohort
Version: 3 Date: 08 Jun 2023
Reviewer's report:
I have read the author´s replies to my comments and I am sufficiently happy with these and the
changes made. I think the manuscript can be accepted for publication with some minor further
changes. As a former editor with a long background in the UK, but who also knows Swedish, I
can see several small inadequacies in the scientific English that stem from translating thoughts
or mode of speaking in Swedish directly to English. There the languages and linguistics  can
differ, such as in the use of definite and indefinite articles. I have taken the liberty of enclosing
a version og the manuscript with corrections in track changes mode and this may be useful for
the authors.
The authors have added the Word „A population-based study“. This is not strictly correct. I
would like to suggest „A study based on a population  cohort“.
It is also good that the authors have exchanged an inappropriate reference 4 for a much better
article, where, however, as so often done, the endometriosis prevalence is said to be higher than
real population studies have suggested. In this the authors´own result of 3.7% is closer to the
truth than what Giudice and Kao state in their almost 20 year old overview article. The other
new references are fine.
In the Discussion (p. 13, l. 317-19)  the authors have the sentence „If endometriosis patients
present with pure gynecological symptoms, which may be unusual according to our current
results, the endometriosis diagnosis may be easier to confirm.” This is not a good sentence. Most
endometriosis patients present and are diagnosed because of symptoms that primarily come from
the internal reproductive organs, not the gastrointestinal tract. Gastrointestinal symptoms do not
usually lead to a diagnosis of endometriosis. Alas so many specialties are locked into their own
viewpoints and doctors have too little training in considering other options than those that relate
to their own field. I think this sentence reflects a stance of this kind and should be changed.
On p. 14, l. 338-39 it says that “The inverse association might be due to increased symptoms
following alcohol consumption and may not reflect causality.“ This likely to be more complex
and  it would suffice to say that the association may not reflect causality.
Page 15, l. 370-372, it says „The main limitation of the present study was that it did not include
participants with a diagnosis given by primary care, resulting in a small endometriosis group.“
Primary care doctors are not particularly alert to the diagnosis of endometriosis, so I am as unsure
as the authors must be about whether this made any difference, partricularly when one considers
how the study material was constructed, also given the use of the National Patient Register as
mentioned in the next sentence.  The authors should reconsider this phrasing.
I would also like to say that it is not necessary to all the time say that something was or was not
„statistically“ significant. Either things are significant or no and it is enough to say just that. It
is also in my opinion not correct to say that there was a trend, but that it was not signficant. A
non-significant trend indicates something that does not exist (p. 13, line 323-4).
The Conclusion repeats too much of what is already said and might focus on the finding that no
No obvious difference in gastrointestinal symptoms was observed between the two conditions.