The Protective Role of Preoperative Stimulation of GABA Before Ileostomy Closure

November 9, 2026 updated by: Wei Guo, Qilu Hospital of Shandong University

The goal of this clinical trial is to explore whether preoperative gamma aminobutyric acid (GABA) lavage of the diverted colon improved postoperative bowel recovery, with time to first flatus as the primary outcome. Participants will be divided into two groups. One group included patients treated with stimulation of GABA prior to ileostomy reversal surgery; the other control group was stimulated with 0.9% saline. Researchers will compare incidence of complications such as postoperative ileus, diarrhea and other parameters such as time to tolerating a diet, start of the passage of flatus, start of the passage of stool, postoperative stay, multi-omic profiling of the gut microbiome and metabolome and serum biochemical measurements evaluating potential systemic effects, etc.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

90

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Shandong
      • Jinan, Shandong, China, 250012
        • Qilu Hospital of Shandong University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • over 18 years of age;
  • body mass index (BMI) 18.5-28 kg/m2;
  • having protective ileostomy after colorectal carcinoma surgery free of disease;
  • with endoscopic and histological confirmation of diversion colitis;
  • no oral antibiotics or probiotic within 3 months;
  • having signed the informed consent.

Exclusion Criteria:

  • under 18 years of age;
  • a history of drug or alcohol abuse;
  • clinical history and histological confirmation of inflammatory bowel disease or other gastrointestinal motility disorders with colorectal involvement;
  • previous abdominal surgery;
  • mental disorders;
  • other serious chronic diseases, such as cardiovascular and cerebrovascular diseases, diabetes, respiratory diseases, etc;
  • serious perioperative complications such as anastomotic rupture after surgery;
  • oral antibiotics or probiotic within three months;
  • participation in any other studies within the past 3 months;
  • refusal to participate in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: preoperative stimulation of diverted colorectal segments with GABA before ileostomy closure surgery

Patients allocated to the GABA group received local preoperative enema stimulation of the diverted distal colorectal segment once daily for four consecutive days before ileostomy closure. For each session, the contents of four GNC GABA 750-mg capsules, providing 3,000 mg of labeled GABA, were dissolved in 100 mL of sterile 0.9% sodium chloride injection manufactured by Shijiazhuang No. 4 Pharmaceutical Co., Ltd. (Shijiazhuang, China), yielding a final nominal GABA concentration of 30 mg/mL. GABA was supplied as commercially available dietary-supplement-grade capsules (GNC Holdings, LLC, Pittsburgh, PA, USA). According to the manufacturer's label, each capsule contained 750 mg of gamma-aminobutyric acid; a numerical analytical purity specification was not provided by the manufacturer. The preparation was made aseptically immediately before administration and infused slowly over 10-20 minutes through a sterile 14-Ch Foley catheter connected to an infusion set.

Foley catheter No.14 Ch connected to an infusion set was introduced through the defunctioned bowel to allow the slow infusion, for 10-20 minutes, of a solution with 3000 mg of GABA diluted in 100 ml of 0.9% physiological saline.

Sham Comparator: control group was stimulated with 0.9% saline

Patients allocated to the sham group received 100 mL sterile 0.9% sodium chloride injection following an identical protocol, including catheter insertion, infusion route, infusion volume, infusion duration, and symptom recording, but without GABA administration. After completion of four enema sessions, all patients underwent ileostomy closure within the subsequent 24 h.

Foley catheter No.14 Ch connected to an infusion set was introduced through the defunctioned bowel to allow the slow infusion, for 10-20 minutes, of 100 ml of 0.9% physiological saline.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
time to first flatus
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

time from the end of surgery to the first passage of flatus

From date of the end of surgery until the date of discharge, assessed up to 20 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
the incidence of POI (Postoperative Ileus)
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

the incidence of POI

From date of the end of surgery until the date of discharge, assessed up to 20 days
time to first passage of stool
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

time to first passage of stool

From date of the end of surgery until the date of discharge, assessed up to 20 days
incidence of watery stool
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

incidence of watery stool

From date of the end of surgery until the date of discharge, assessed up to 20 days
time to first liquid intake
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

time to first liquid intake

From date of the end of surgery until the date of discharge, assessed up to 20 days
time to tolerance of a solid diet
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

time to tolerance of a solid diet

From date of the end of surgery until the date of discharge, assessed up to 20 days
total and postoperative lengths of hospital stay
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

total and postoperative lengths of hospital stay

From date of the end of surgery until the date of discharge, assessed up to 20 days
profiling of the gut microbiome
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

metagenomic sequencing of the gut microbiota.

From date of the end of surgery until the date of discharge, assessed up to 20 days
profiling of metabolome
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

metabolomic profiling of colonic lavage fluid and plasma.

From date of the end of surgery until the date of discharge, assessed up to 20 days
serum biochemical measurements
Time Frame: From date of the end of surgery until the date of discharge, assessed up to 20 days

biochemical indicators of hepatic and renal function, lipid metabolism, and glucose metabolism

From date of the end of surgery until the date of discharge, assessed up to 20 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 20, 2023

Primary Completion (Actual)

April 30, 2024

Study Completion (Actual)

August 15, 2024

Study Registration Dates

First Submitted

May 30, 2023

First Submitted That Met QC Criteria

June 7, 2023

First Posted (Actual)

June 15, 2023

Study Record Updates

Last Update Posted (Actual)

November 13, 2026

Last Update Submitted That Met QC Criteria

November 9, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • KYLL-202212-066-1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

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