Effect of Oral Laxative Use Before Colorectal Surgery on Intraoperative Surgical Difficulty (OLAX-CRC)

This prospective randomized pilot study will evaluate whether the use of an oral laxative before elective laparoscopic colorectal surgery affects small-bowel diameter and intraoperative surgical difficulty. Adult patients scheduled for elective laparoscopic colorectal resection will be randomly assigned to receive either oral laxative plus rectal enema preparation or rectal enema preparation alone. During surgery, the diameters of the jejunum and ileum will be measured using a standardized method. The study will also compare operative difficulty, bowel manipulation time, operation duration, need for additional ports, conversion to open surgery, intraoperative complications, blood loss, and early postoperative outcomes between the two groups. The findings may help clarify whether oral laxative use influences intraoperative conditions during laparoscopic colorectal surgery.

Study Overview

• Status: Recruiting
• Conditions: Mechanical Bowel Preparation; Colorectal Diseases
• Intervention / Treatment: Drug: Oral Laxative; Drug: Rectal Enema

Detailed Description

Mechanical bowel preparation is commonly used before elective colorectal surgery. Although its effects on postoperative outcomes have been widely investigated, limited evidence is available regarding the effect of oral laxatives on intraoperative small-bowel distension and technical difficulty during laparoscopic colorectal surgery. Increased intraluminal fluid following oral laxative administration may lead to small-bowel distension, potentially impairing surgical exposure and increasing the need for bowel manipulation.

In this study, small-bowel diameter will be assessed intraoperatively using a standardized measurement method after laparoscopic access and establishment of pneumoperitoneum. Jejunal diameter will be measured approximately 50 cm distal to the ligament of Treitz, and ileal diameter approximately 20 cm proximal to the ileocecal valve. Measurements will be performed in the transverse plane without applying mesenteric tension and, when feasible, the mean of two measurements will be recorded. At the end of the operation, the operating surgeon will assess overall operative difficulty using a Likert-type scale ranging from very easy to very difficult. This pilot study is intended to provide preliminary evidence for the design of future adequately powered studies and to support the evaluation of current bowel-preparation practices.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: İbrahim Doğan; Phone Number: +905313884966; Email: dogan_203@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Van
    • Van, Van, Turkey (Türkiye), 65300
      • Recruiting
      • University of Health Sciences Türkiye, Van Training and Research Hospital
      • Contact: İbrahim Doğan; Phone Number: +905313884966; Email: dogan_203@hotmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older
• Scheduled for elective laparoscopic colorectal resection
• American Society of Anesthesiologists (ASA) physical status I-III
• Able and willing to provide written informed consent

Exclusion Criteria:

• Requirement for emergency surgery
• Mechanical intestinal obstruction, gastrointestinal perforation, or generalized peritonitis
• Anticipated extensive intra-abdominal adhesions
• Active inflammatory bowel disease
• Pregnancy
• Serious systemic disease constituting a contraindication to oral laxative use
• Inability to perform standardized intraoperative small-bowel diameter measurements

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Oral Laxative Plus Rectal Enema; Participants assigned to this arm will receive preoperative bowel preparation consisting of an oral laxative combined with a rectal enema before elective laparoscopic colorectal surgery.	Drug: Oral Laxative; Participants assigned to the experimental arm will receive an oral laxative as part of preoperative mechanical bowel preparation, in addition to a rectal enema, before elective laparoscopic colorectal surgery. The oral laxative will be administered according to the institution's standard preoperative bowel preparation protocol.; Drug: Rectal Enema; Participants in both study arms will receive a rectal enema as part of preoperative bowel preparation before elective laparoscopic colorectal surgery. Participants in the comparator arm will receive the rectal enema without an oral laxative.
Active Comparator: Rectal Enema Alone; Participants assigned to this arm will receive preoperative bowel preparation consisting of a rectal enema alone, without an oral laxative, before elective laparoscopic colorectal surgery.	Drug: Rectal Enema; Participants in both study arms will receive a rectal enema as part of preoperative bowel preparation before elective laparoscopic colorectal surgery. Participants in the comparator arm will receive the rectal enema without an oral laxative.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative Jejunal Diameter	Jejunal diameter will be measured in centimeters approximately 50 cm distal to the ligament of Treitz, in the transverse plane, under standard pneumoperitoneum pressure and without applying mesenteric tension. When feasible, two measurements will be obtained and their mean will be recorded.	Intraoperatively, after laparoscopic access and establishment of pneumoperitoneum
Intraoperative Ileal Diameter	Ileal diameter will be measured in centimeters approximately 20 cm proximal to the ileocecal valve, in the transverse plane, under standard pneumoperitoneum pressure and without applying mesenteric tension. When feasible, two measurements will be obtained and their mean will be recorded.	Intraoperatively, after laparoscopic access and establishment of pneumoperitoneum

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Operative Difficulty Score	Overall operative difficulty will be assessed by the operating surgeon at the end of the procedure using a 5-point Likert scale: 1 = very easy, 2 = easy, 3 = moderate, 4 = difficult, and 5 = very difficult. Higher scores indicate greater operative difficulty.	At the end of surgery, on the day of the procedure
Estimated Intraoperative Blood Loss	The estimated volume of blood lost during surgery, as recorded in the operative and anesthesia records.	Intraoperatively, on the day of surgery
Incidence of Intraoperative Serosal Injury	The number of participants who experience an unintended serosal injury during surgery, as documented in the operative record.	Intraoperatively, on the day of surgery
Incidence of Intraoperative Organ Injury	The number of participants who experience an unintended injury to an intra-abdominal organ during surgery, as documented in the operative record.	Intraoperatively, on the day of surgery
Incidence of Intraoperative Bleeding Requiring Intervention	The number of participants who experience intraoperative bleeding requiring an additional hemostatic intervention beyond routine surgical hemostasis.	Intraoperatively, on the day of surgery
Requirement for an Additional Laparoscopic Port	The number of participants in whom placement of at least one additional laparoscopic port beyond the planned port configuration is required to complete the procedure.	Intraoperatively, on the day of surgery
Conversion From Laparoscopic to Open Surgery	The number of participants whose planned laparoscopic procedure is converted to an open surgical approach.	Intraoperatively, on the day of surgery
Incidence of Any Postoperative Complication Within 30 Days	The number of participants who experience at least one surgery-related postoperative complication within 30 days after surgery. Each participant will be counted once, regardless of the number of complications experienced.	From the day of surgery through postoperative day 30
Incidence of Anastomotic Leakage Within 30 Days	The number of participants who develop an anastomotic leak within 30 days after surgery, as documented by clinical, radiological, endoscopic, operative, or drainage findings.	From the day of surgery through postoperative day 30
Incidence of Surgical Site Infection Within 30 Days	The number of participants who develop a surgical site infection within 30 days after surgery, including superficial incisional, deep incisional, or organ/space infection.	From the day of surgery through postoperative day 30
Incidence of Postoperative Ileus Within 30 Days	The number of participants who develop postoperative ileus within 30 days after surgery, as documented in the medical record based on delayed recovery or interruption of gastrointestinal function.	From the day of surgery through postoperative day 30
Time Required for Bowel Manipulation and Displacement	The time required to manipulate the bowel and displace it from the operative field during surgery.	Intraoperatively, on the day of surgery
Time Required for Intraoperative Bowel Diameter Measurements	The time required to perform intraoperative measurements of the jejunal and ileal diameters.	Intraoperatively, on the day of surgery
Time Required to Complete the Anastomosis	The time from initiation of anastomosis construction to completion of the anastomosis during surgery.	Intraoperatively, on the day of surgery
Total Operation Time	The total duration of the surgical procedure, defined as the time from skin incision to completion of skin closure.	Intraoperatively, on the day of surgery

Collaborators and Investigators

• Sponsor: Van Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): May 22, 2026
• Primary Completion (Estimated): May 22, 2027
• Study Completion (Estimated): June 22, 2027

Study Registration Dates

• First Submitted: September 5, 2026
• First Submitted That Met QC Criteria: September 10, 2026
• First Posted (Actual): September 15, 2026

Study Record Updates

• Last Update Posted (Actual): September 15, 2026
• Last Update Submitted That Met QC Criteria: September 10, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Randomized Controlled Trial; Colorectal Surgery; Laparoscopic Surgery; Mechanical Bowel Preparation; Oral Laxative
• Additional Relevant MeSH Terms: Gastrointestinal Agents; Pharmacologic Actions; Chemical Actions and Uses; Therapeutic Uses; Laxatives
• Other Study ID Numbers: 2026/05-02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No