Impact of Ambulatory Physiological Stimulation of the Efferent Limb Prior to Ileostomy Closure on Colorectal Microbiota Composition and Histopathological Findings (STIMIC)

June 8, 2026 updated by: Romina Pena, Hospital Clinic of Barcelona

The STIMIC Trial: A Multicenter Randomized Control Trial Evaluating the Impact of Ambulatory Physiological Stimulation of the Efferent Limb Prior to Ileostomy Closure on Colorectal Microbiota Composition and Histopathological Findings

BACKGROUND Loop ileostomies are a type of stoma frequently used to protect high-risk colorectal anastomoses (surgical reconnection of the intestines), for example following rectal cancer resection. Temporary diversion of intestinal transit does not reduce the risk of anastomotic failure, but it does lower the morbidity and mortality associated with potential pelvic sepsis. Unfortunately, a second surgical procedure is required to restore intestinal continuity, and this carries its own risk of complications, the most common being postoperative ileus (temporary paralysis of bowel motility associated with abdominal distension, absence of bowel movements, nausea, and vomiting), which occurs in up to 20% of cases.

Several strategies have been proposed to reduce this problem, including stimulation of the efferent limb of the ileostomy (the part that is connected to the unused colon). This intervention consists of instilling a substance through the efferent limb of the ileostomy into the colon, simulating natural intestinal transit. It emerged as a harmless alternative aimed at reversing changes in the excluded colon in preparation for restoration of intestinal continuity. Several Spanish studies have investigated this technique, concluding that it is safe and significantly reduces the rate of postoperative ileus, thereby shortening hospital stay. Regarding the mechanism by which this intervention may be effective, there are studies investigating the changes that occur during diversion of intestinal transit:

  1. Histopathology: reduced muscular contractility and the presence of intestinal villi in the efferent intestinal limb and excluded colon, which improve once intestinal flow is restored.
  2. Microbiome: significant loss of microbiota in the defunctionalized colon, which progressively recovers with natural intestinal transit and reintroduction of a fiber-rich diet.

Structural and microbiota-related changes favor the development of diversion colitis, a condition associated with erratic bowel habits once intestinal transit is restored. In an attempt to reverse this condition, several products have been tested for stimulation of the efferent limb of the ileostomy: probiotics, short chain fatty acids, saline solution with a thickening agent, and the patient's own intestinal contents, a well-tolerated and effective technique, in some cases superior to saline-based alternatives.

Overall, the available evidence is of low quality due to the limited number of patients studied and protocol variability. For this reason, we propose the implementation of a protocol for stimulation of the distal ileostomy limb prior to ileostomy closure, either with saline solution and thickening agent (the most widely described technique in the literature) or physiological stimulation using the patient's own intestinal contents.

The protocol consists of several sessions in which the instilled volume is progressively increased. This intervention will be performed on an outpatient basis, once daily, during the two weeks prior to surgery.

This process promotes the onset of bowel movements through the anus, which progressively become more formed and less frequent, approaching a more normal bowel habit. Only minor adverse effects have been described with this technique, including cramp-like abdominal pain in 27.6% of sessions. Recently, a nationwide study confirmed the favorable clinical outcomes following distal ileostomy limb stimulation before ileostomy closure. However, to our knowledge, no studies have evaluated its effect on intestinal microbiota.

HYPOTHESIS Distal limb stimulation of the ileostomy before its closure helps in the recovery of the colorectal microbiome and tissue. This associates with lower postoperative complications, specially postoperative ileus.

OBJECTIVES To gain knowledge regarding changes in intestinal microbiota composition before and after stimulation, in order to better understand recovery of intestinal function following this procedure. We will also analyze outcomes after ileostomy closure following efferent limb stimulation, determining the incidence of postoperative complications, particularly postoperative ileus.

METHODOLOGY

Patients will be randomly assigned to one of three groups:

  1. Control (no intervention other than the usual preoperative protocol)
  2. Stimulation with serum and thickener
  3. Stimulation with own stoma output

Samples will be collected in all patients:

  1. Stoma output
  2. Stool, before stimulation, if performed
  3. Stool, after stimulation, if performed
  4. Stool, a month after surgery

For a group of patients, the ones recruited at Hospital Clínic, rectal biopsies will also be collected before and after stimulation, to compare the effect of the treatment in the colonic tissue. We will collect clinical data during the whole process regarding postoperative complications.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

90

Phase

  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact Backup

  • Name: Miguel Pera, MD, PhD
  • Phone Number: 5559 +34 932275400
  • Email: PERA@clinic.cat

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion criteria:

  1. Patients 18 yo and older, with a loop ileostomy after colorectal surgery for malignant or benign disease and a barium enema that rules out colorectal anastomotic leak or stenosis.
  2. Patients must be self-sufficient in their stoma care or dispose of assistance by a family member or healthcare provider.
  3. Patients must reside no further than 50km from the hospital and dispose of postoperative home-assistance by a family member or healthcare provider.

Exclusion criteria:

  1. Patients with a terminal ileostomy or a closed distal limb, inaccesible to preoperative stimulation.
  2. Patients with the diagnosis of inflammatory bowel disease.
  3. Patients incapable of comprehending or signing the informed consent.

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Control
No efferent limb stimulation.
Active Comparator: Serum stimulation
Efferent limb stimulation with serum and thickener.
Other: Serum stimulation
The intervention has been described in previous studies, but the investigation of the microbiome changes associated with the obtained clinical results hasn't been described to date. Also, a study with three arms hasn't been published to date.
Other Names:
  • efferent limb stimulation
  • physiological stimulation
Active Comparator: Physiological stimulation
Efferent limb stimulation with the patient's own stoma output.
Other: Physiological stimulation
The intervention has been described in previous studies, but the investigation of the microbiome changes associated with the obtained clinical results hasn't been described to date. Also, a study with three arms hasn't been published to date.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in colorectal microbiome before and after efferent limb stimulation prior to stoma closure.
Time Frame: From enrollment to the end of follow-up at 3 months.
Descriptive analysis of the microbiome profiles of the three groups of patients (control, stimulation with serum, stimulation with own stoma output).
From enrollment to the end of follow-up at 3 months.
Changes in colorectal tissue before and after efferent limb stimulation prior to stoma closure.
Time Frame: From the time of first biopsy (before stimulation) to the second one (surgery day).
Description of the tissue obtained by biopsy of the rectum, before and after stimulation of the ileostomy.
From the time of first biopsy (before stimulation) to the second one (surgery day).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative complications after stoma closure.
Time Frame: From the surgery (ileostomy closure) to 30 days follow-up.
Incidence of postoperative ileus and surgical site infection.
From the surgery (ileostomy closure) to 30 days follow-up.
Functional outcomes after efferent limb stimulation (LARS score)
Time Frame: From enrollment to the end of follow-up a 3 months.

Description of the funcional (defecatory) outcomes after ileostomy closure.

LARS (Low Anterior Resection Syndrome) score: total score ranges from 0-42 points (0-20 is equivalent no LARS, 21-29 points to minor LARS, and 30-42 to major LARS).
From enrollment to the end of follow-up a 3 months.
Functional outcomes after efferent limb stimulation (Vaizey score)
Time Frame: From enrollment to the end of follow-up at 3 months.

Description of the funcional (defecatory) outcomes after ileostomy closure.

Vaizey score (also known as the St. Mark's Incontinence Score): total score ranges from 0 (perfect continence) to 24 points (severe incontinence).
From enrollment to the end of follow-up at 3 months.

Collaborators and Investigators

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

Sponsor

Hospital Clinic of Barcelona

Collaborators

Hospital Mutua de Terrassa
Althaia Xarxa Assistencial Universitària de Manresa

Investigators

  • Principal Investigator: Romina Pena, MD, Hospital Clinic of Barcelona

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 (Estimated)

June 1, 2026

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

March 1, 2028

Study Registration Dates

First Submitted

May 26, 2026

First Submitted That Met QC Criteria

June 8, 2026

First Posted (Actual)

June 10, 2026

Study Record Updates

Last Update Posted (Actual)

June 10, 2026

Last Update Submitted That Met QC Criteria

June 8, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • HCB/2026/0615

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All IPD that underlie results in a publication.

IPD Sharing Time Frame

Beginning 1 month and ending 1 year after the publication of results.

IPD Sharing Access Criteria

IPD and supporting information of this study might be accessed by fellow researchers with a future study, related to our published findings. Researchers must submit a request for data sharing by contacting the principal investigator, who will also be the corresponding author in the future published data. The request to access IPD will be reviewed by the principal investigator (Romina Pena).

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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