Review for 10.1186/s12876-025-04171-9 (2025)

Title: Clinical Relevance of Transperineal Ultrasound Compared with Anorectal Manometry
for the Evaluation of Female Patients with Obstructive Defecation Syndrome
Version: 0 Date: 22 May 2025
Reviewer's report:
This manuscript attempts to explore the diagnostic correlation between transperineal ultrasound
(TPUS) and anorectal manometry (ARM) in women with obstructive defecation syndrome
(ODS). While the study addresses a clinically relevant topic in pelvic floor dysfunction, its
current form contains several major shortcomings that significantly detract from its scientific
validity, interpretative clarity, and potential contribution to the literature.
The central premise of the paper rests on establishing a bidirectional relationship between
anatomical findings on TPUS and functional abnormalities detected via ARM. However,
the study design lacks a prospective structure, and the retrospective nature—coupled
with significant missing demographic data—weakens the internal validity. Moreover, the
justification for dual-modality usage is undermined by the finding that most TPUS parameters
do not significantly predict ARM abnormalities and vice versa. Despite this, the authors propose
routine combined use of both modalities in clinical practice, a conclusion that appears overstated
given the modest diagnostic concordance demonstrated in the data.
Statistically, the use of sensitivity, specificity, and odds ratios is appropriate, yet the AUROC
values are absent for most of the reported relationships, making the strength of these diagnostic
tests difficult to assess in terms of clinical utility. Additionally, several associations—such
as inverse correlations between defecatory pressure and rectocele—are biologically plausible
but were interpreted with overstated confidence despite borderline OR values and broad
confidence intervals. There is also an insufficient exploration of confounding variables such as
parity, hysterectomy status, and age, which were either inconsistently reported or statistically
unadjusted.
Methodologically, the categorization of abnormalities in TPUS and ARM appears largely
dependent on literature-derived thresholds, but no interobserver agreement statistics were
provided for either modality. This omission is critical given the known operator-dependency
of both TPUS and ARM. The criteria for defining dyssynergia using anorectal angle changes
on ultrasound are also inadequately explained and deviate from internationally accepted criteria
(e.g., London Classification), raising concerns about external validity and replicability.
Furthermore, the manuscript does not sufficiently address limitations that are inherent in the
chosen imaging and physiological tests, such as the positional differences during testing, lack
of rectal balloon expulsion test for corroborative assessment, and potential referral bias due to
patient selection from a single tertiary center.
The language throughout the manuscript is often verbose and lacks precision, with frequent
grammatical inconsistencies, overuse of explanatory clauses, and redundant phrases. Many
sentences are excessively long and convoluted, detracting from clarity and readability. The
manuscript would greatly benefit from thorough linguistic editing to improve flow and
professionalism.
In terms of literature, references are generally appropriate, but several key studies on defecatory
disorders and the limitations of ARM or TPUS in isolation are absent. The discussion is
disproportionately long and occasionally reiterates points already established in the results
section, rather than offering nuanced insights or alternative interpretations.
In conclusion, this study addresses a topic of interest but is limited by methodological flaws,
overinterpretation of modest associations, lack of clear clinical applicability, and significant
language issues. Unless these issues are substantively addressed, the manuscript in its current
form does not meet the standards for publication in BMC Gastroenterology.