Review for 10.1186/s12876-025-04016-5 (2025)

Title: The effect of chewing gum on postoperative ileus after laparotomy for gastroduodenal
perforations: A randomized controlled trial.
Version: 3 Date: 27 Dec 2024
Reviewer:  Mohamed H. Zidan
Reviewer's report:
Dear Authors,
Re: "The effect of chewing gum on postoperative ileus after laparotomy for gastroduodenal
perforations: A randomized controlled trial"
Thank you for submitting your manuscript for review. This RCT addresses an important
clinical question about the utility of chewing gum (CG) in reducing postoperative ileus (POI)
duration following laparotomy for gastroduodenal perforations (GDP). The study has the
potential to contribute meaningfully to the field, particularly in low-resource settings, by
evaluating an accessible and low-cost intervention. However, after a detailed review of the
manuscript, protocol, supplementary materials, and authors’ responses to prior comments,
several methodological, statistical, and reporting concerns arise that warrant attention.
The study adheres to its stated protocol in most respects, including alignment of study objectives,
outcomes, and the randomized design. The inclusion of permuted block randomization
and blinded outcome assessment enhances reliability. However, deviations such as unclear
adherence to the planned sample size and retrospective trial registration raise concerns about
transparency and internal validity. While the manuscript cites its protocol appropriately, reliance
on external documentation for methodological details, rather than fully elaborating them within
the text, detracts from its standalone completeness.
The results demonstrate a significant reduction in POI duration in the CG group compared to
the control group (median 28.5 hours vs. 50 hours; p = 0.002), as well as a shorter hospital stay
(4.5 days vs. 7 days; p = 0.007). However, the absence of statistically significant differences in
morbidity and complications limits the broader applicability of these findings. The physiological
plausibility of CG's effects on bowel motility is briefly mentioned but insufficiently explored.
Future iterations of this manuscript would benefit from a deeper discussion of the mechanisms
underlying CG's effects in the context of severe peritonitis and postoperative recovery.
The statistical approach described in the protocol included nonparametric methods for non-
normal data, yet the manuscript does not provide sufficient details on whether assumptions of
normality were tested or how ties were addressed in the analyses. Additionally, discrepancies in
reporting exact p-values for secondary outcomes and subgroup analyses reduce confidence in the
robustness of the findings. For instance, while adherence to CG was cited as a factor influencing
results, subgroup analysis or sensitivity testing is not provided to support these claims.
The authors have addressed many reviewer concerns, particularly by ensuring adherence
to CONSORT guidelines and expanding their discussion of limitations. However, several
points remain insufficiently clarified. The justification for excluding patients with significant
comorbidities such as uncontrolled diabetes is acknowledged but reduces the study’s
generalizability. Moreover, the retrospective nature of the trial registration undermines the
credibility of the results, even with the authors’ detailed explanation.
The manuscript effectively presents its data in figures and tables, including a clear CONSORT
flow diagram. However, graphical representations such as boxplots or Kaplan-Meier curves for
outcomes like POI duration and hospital stay would enhance the readability and accessibility
of the results. The supplementary files and raw data reveal some inconsistencies, particularly
regarding adherence rates and missing information on outlier treatment, which should be
addressed for improved transparency.
In summary, the manuscript makes a valuable contribution to understanding the role of CG
in managing POI. However, the methodological deviations, data inconsistencies, and limited
discussion of key aspects such as physiological mechanisms and statistical robustness must be
resolved to ensure the reliability and applicability of the findings. With these revisions, the study
will be well-positioned to influence clinical practice and future research.
Kind regards