Lf-rTMS Attenuates Visceral Pain in Irritable Bowel Syndrome With Diarrhea

November 18, 2025 updated by: The First Affiliated Hospital of Soochow University

Low-frequency Repetitive Transcranial Magnetic Stimulation Attenuates Visceral Pain in Irritable Bowel Syndrome With Diarrhea Via Inhibition of the Medial Prefrontal Cortex

Objectives: To identify a central hub of visceral pain in IBS-D and elucidate the mechanism by which repetitive transcranial magnetic stimulation (rTMS) confers analgesic effects.

Methods: A total of 42 IBS-D patients were recruited and randomly assigned (1:1) to the sham rTMS or the rTMS group. A nested cohort of 21 IBS-D participants who completed baseline fMRI assessments prior to randomization was included. Consistent with the randomization procedure，these individuals were evenly distributed between the two groups. Both participants and outcome assessors remained blinded to treatment allocation throughout the study. All patients completed the two-week intervention and were included in the final analysis.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Background：Chronic visceral pain in irritable bowel syndrome with diarrhea (IBS-D) is a profound therapeutic challenge. While aberrant central processing is implicated, the key brain regions driving this visceral pain and their suitability as neuromodulatory targets remain undefined.

Methods: Participants were randomly assigned (1:1) to the sham rTMS or rTMS group using a computer-generated randomization sequence created by an independent researcher who was not involved in recruitment, treatment, or outcome assessment. Allocation concealment was ensured using sequentially numbered, opaque, sealed envelopes, which were opened only after baseline evaluations were completed.

Both participants and outcome assessors were blinded to treatment allocation. The rTMS operators were not involved in data collection or analysis. For the sham condition, the coil was positioned identically over the mPFC with magnetic output disabled, and prerecorded clicking sounds were delivered to mimic the acoustic sensation of stimulation. Participants were asked not to discuss treatment sensations with assessors. Scale raters and fMRI analysts remained blinded until all analyses were finalized.

For the nested fMRI cohort, randomization and blinding procedures were identical, with group allocation revealed only after preprocessing and statistical analysis had been completed.

Study Type

Interventional

Enrollment (Estimated)

42

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 Locations

  • China
    • Jiangsu
      • Suzhou, Jiangsu, China, 215006
        • Recruiting
        • The First Affiliated Hospital of Soochow University
        • Principal Investigator:
          • Rui Li, Dr.
        • Contact:
        • Principal Investigator:
          • Ruixia Weng
        • Contact:

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

All diagnoses were made by board-certified gastroenterologists. Eligible participants met the following inclusion criteria: (1) age between 18 and 75 years; (2) fulfillment of the Rome IV diagnostic criteria for IBS-D. Exclusion criteria included: (1) presence of inflammatory or other organic gastrointestinal diseases; (2) diagnosed psychiatric disorders; (3) history of anorectal, intestinal, or abdominal surgery; (4) pregnancy or lactation; (5) presence of metallic implants or cardiac pacemakers.

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
Sham Comparator: Sham rTMS Group
For the sham rTMS group, the coil was placed over the mPFC with the rTMS function disabled, and pre-recorded acoustic artifacts were played to mimic the auditory experience of the rTMS group.
Device: Sham (No Treatment)
For the sham rTMS group, the coil was placed over the mPFC with the rTMS function disabled, and pre-recorded acoustic artifacts were played to mimic the auditory experience of the rTMS group.
Active Comparator: rTMS Group
Low-frequency rTMS (1 Hz) was applied to the mPFC using a TMS stimulator at 80% resting motion threshold intensity.
Device: Repetitive Transcranial Magnetic Stimulation
A figure-of-eight coil is used to apply active low-frequency (1 Hz) rTMS to the corresponding representation area of theprefrontal cortex (mPFC). The treatment is administered for 20 minutes daily for a total of 2 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Visceral Sensitivity Index
Time Frame: 2 weeks of treatment
(1) Clinical control: After the course of treatment, clinical symptoms disappear; (2) Significant effect: After the course of treatment, the symptom grading is reduced by 2 levels; (3) Effective: After the course of treatment, the symptom grading is reduced by 1 level; (4) Ineffective: After treatment, those who do not meet the above standards.
2 weeks of treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
IBS-symptom severity score
Time Frame: 2 weeks of treatment
The criteria were based on the IBS Symptom Severity Score (IBS-SSS), a hierarchical efficacy assessment method.The IBS-SSS consists of five entries assessing the degree of abdominal pain and discomfort, frequency of bdominal pain episodes, the degree of abdominal distension and discomfort, the degree of satisfaction with bowel habits and behaviors, and the degree of impact of intestinal symptoms on life,with a total score of 500 points. A score of 75-175 is considered mild, 176-300 is moderate, and over 300 is severe. Cure was defined as a total IBS symptom severity of less than 75; efficacy was defined as 2-level improvement in total score(e.g., symptoms improved from severe to mild); validity was defined as a 1-level improvement in tatal(e.g., symptoms improved from severe to moderate or symptoms from moderate to mild); and invalidity was defined as no improvement or deterioration in total score.
2 weeks of treatment

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
anorectal manometry
Time Frame: 2 weeks of treatment
Anorectal manometry was performed on the subjects before and after treatment and the subjects' rectal primary sensory thresholds were recorded. Rectal initial sensory thresholds between 20-90ml were considered normal , less than 20ml was considered as sensitivity rectal sensory, and cure meant that the IBS patients had their rectal initial sensory recordings restored to between 20-90ml.
2 weeks of treatment

Collaborators and Investigators

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

Sponsor

The First Affiliated Hospital of Soochow University

Investigators

  • Principal Investigator: Rui Li, Dr., The First Affiliated Hospital of Soochow University

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)

August 1, 2024

Primary Completion (Estimated)

December 25, 2025

Study Completion (Estimated)

January 25, 2026

Study Registration Dates

First Submitted

December 24, 2024

First Submitted That Met QC Criteria

December 24, 2024

First Posted (Actual)

January 3, 2025

Study Record Updates

Last Update Posted (Actual)

November 21, 2025

Last Update Submitted That Met QC Criteria

November 18, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024-KY-08
  • BE2023710 (Other Grant/Funding Number: Jiangsu Provincial Department of Science and Technology)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

This clinical research protocol is just beginning to be studied at this time and sharing is not recommended at this time.

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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