The goal of this clinical trial is to compare a standardized 3-day bowel preparation protocol with a rectal enema before laparoscopic surgery for endometrial cancer. The study will evaluate whether the dietary bowel preparation protocol can be used instead of a rectal enema while maintaining an adequate surgical view during surgery.

The main questions it aims to answer are:

• Can the dietary bowel preparation protocol provide surgical exposure comparable to a rectal enema?
• Can the dietary bowel preparation protocol reduce the minimum Trendelenburg position and pneumoperitoneum pressure required to obtain an adequate surgical view?
• Does either bowel preparation method cause more discomfort or side effects before surgery?

Researchers will compare a standardized 3-day bowel preparation protocol with a rectal enema before surgery.

Participants will:

• Be randomly assigned to receive either a standardized 3-day bowel preparation protocol or a rectal enema before surgery.
• Undergo standard laparoscopic surgery for endometrial cancer.
• Have surgical exposure, the minimum Trendelenburg position, the minimum pneumoperitoneum pressure, operative outcomes, postoperative recovery, and bowel preparation-related symptoms and discomfort assessed as part of routine clinical care.

Adequate bowel preparation is important for achieving optimal surgical exposure during laparoscopic surgery for endometrial cancer. Inadequate bowel preparation may impair visualization of the operative field, requiring steeper Trendelenburg positioning and higher pneumoperitoneum pressures, which may increase the physiological burden of surgery and affect operative performance.

Mechanical bowel preparation with rectal enema is commonly used before gynecologic surgery, although its routine use remains controversial because evidence supporting its clinical benefit is limited. A standardized 3-day bowel preparation protocol may improve patient tolerance while maintaining adequate surgical conditions. However, prospective randomized studies comparing these two approaches specifically in laparoscopic endometrial cancer surgery remain limited.

This prospective randomized controlled trial will compare a standardized 3-day bowel preparation protocol with a preoperative rectal enema before laparoscopic surgery for endometrial cancer. The primary objective is to determine whether the dietary bowel preparation protocol can provide surgical conditions comparable to those achieved with rectal enema.

In addition to subjective assessment of surgical exposure, the study will evaluate objective intraoperative parameters, including the minimum Trendelenburg position and the minimum pneumoperitoneum pressure required to maintain an adequate surgical view. Operative outcomes, postoperative recovery, patient tolerance of the bowel preparation methods, and bowel preparation-related symptoms will also be evaluated.

The findings of this study may help optimize preoperative bowel preparation strategies, reduce unnecessary patient burden, and support evidence-based perioperative care for patients undergoing laparoscopic surgery for endometrial cancer.

Inclusion Criteria:

• Female participants aged 18 to 90 years.
• Scheduled to undergo elective laparoscopic surgery for endometrial cancer.
• Willing and able to provide written informed consent.

Exclusion Criteria:

• Planned open (abdominal) surgery.
• Known allergy or contraindication to sodium phosphate rectal enema.
• Age over 90 years.
• Refusal or inability to provide written informed consent.

De-identified individual participant data underlying the published results, together with a data dictionary, will be made available upon reasonable request to the corresponding investigator. Data will be shared only after publication of the primary study results and subject to institutional approval, a scientifically sound research proposal, and execution of a data use agreement. Additional data may be considered on a case-by-case basis at the discretion of the principal investigator.

Beginning 6 months after publication of the primary study results and ending 3 years after publication.

Access will be considered for qualified researchers conducting scientifically sound research. Requests must include a research proposal and, where appropriate, a statistical analysis plan. All requests will be reviewed by the principal investigator and approved according to institutional policies. Approved researchers will be required to sign a data use agreement before receiving de-identified data.

Because of the nature of the interventions, participants and the study nurse responsible for preoperative bowel preparation cannot be blinded. Operating surgeons assessing the intraoperative primary outcomes will remain unaware of treatment allocation until completion of the intraoperative assessment. Postoperative data collection and statistical analyses will be performed by the study investigators.