Trans Auricular Vagal Nerve Stimulation in Patients With IBS-C

NCT07662083 | Not Yet Recruiting FDA Device

• 1 other identifier: STUDY00000105
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

This study evaluates the efficacy and safety of transcutaneous auricular vagus nerve stimulation (ta-VNS) in adults with constipation-predominant irritable bowel syndrome (IBS-C). Participants will be randomized to receive either active or sham stimulation using a non-invasive auricular device over a 60-day period. The primary objectives are to assess changes in symptom severity and quality of life using validated instruments, including the IBS Symptom Severity Scale (IBS-SSS) and the IBS Quality of Life questionnaire (IBS-QOL). Secondary assessments include safety and participant compliance. This study aims to determine whether ta-VNS is an effective non-invasive therapeutic modality for improving symptoms and quality of life in patients with IBS-C.

Conditions

Irritable Bowel Syndrome (IBS-C)

Keywords

Trans Auricular Vagal Nerve Stimulation

Outcome Measures

Primary Outcomes (2)

• Change From Baseline in IBS Symptom Severity Scale (IBS-SSS) Score at Day 60

  Evaluate the effect of transcutaneous auricular vagus nerve stimulation (ta-VNS) on symptom severity in patients with IBS-C using the IBS Symptom Severity Scale (IBS-SSS). The IBS-SSS assesses abdominal pain severity and frequency, abdominal distension, bowel habit satisfaction, and interference with quality of life. Scores range from 0 to 500, with higher scores indicating more severe symptoms (≤75 remission, 75-174 mild, 175-299 moderate, 300-500 severe). The outcome measure is defined as the change in IBS-SSS score from baseline to Day 60.

  Baseline to Day 60

• Change From Baseline in IBS Quality of Life (IBS-QOL) Total Score at Day 60

  Evaluate the impact of ta-VNS on quality of life in patients with IBS-C using the IBS Quality of Life (IBS-QOL) questionnaire. The IBS-QOL is a 34-item validated instrument scored on a 5-point Likert scale and converted into a total score ranging from 0 to 100, with higher scores indicating better quality of life. The outcome measure is defined as the change in IBS-QOL total score from baseline to Day 60.

  Baseline to Day 60

Secondary Outcomes (3)

• Incidence of Adverse Events

  Baseline through Day 60

• Participant Compliance With ta-VNS Intervention

  Baseline to Day 60

• Change From Baseline in IBS Quality of Life (IBS-QOL) Domain Scores at Day 60

  Baseline to Day 60

Study Arms (2)

Transcutaneous Auricular Vagus Nerve Stimulation (ta-VNS)

EXPERIMENTAL

Participants will receive active transcutaneous auricular vagus nerve stimulation (ta-VNS) using the Parasym device (Parasym Health, Inc., London, UK). The device delivers electrical stimulation to the auricular branch of the vagus nerve via an ear clip. Stimulation will be administered once daily for 30 minutes over 60 days at a consistent time chosen by the participant. Stimulation parameters are set at 25 Hz and 250 microseconds, with intensity adjusted to just below the participant's discomfort threshold (0-36 mA).

Device: Transcutaneous Auricular Vagus Nerve Stimulation (ta-VNS)

Sham Transcutaneous Auricular Vagus Nerve Stimulation

SHAM COMPARATOR

Participants will receive sham stimulation using an identical-appearing Parasym device. The device delivers a brief, low-level electrical output at the start of each session, which ramps down to zero and provides no stimulation for the remainder of the session. Sessions will last 30 minutes daily for 60 days at a consistent time of the participant's choosing. The device will look, feel, and sound identical to the active device to maintain blinding.

Device: Sham Transcutaneous Auricular Vagus Nerve Stimulation

Interventions

Transcutaneous Auricular Vagus Nerve Stimulation (ta-VNS) DEVICE

Delivery of non-invasive electrical stimulation to the auricular branch of the vagus nerve using the Parasym device. Stimulation is applied via an ear clip at 25 Hz and 250 microseconds, with intensity titrated to just below discomfort (0-36 mA). Administered for 30 minutes daily over 60 days.

Transcutaneous Auricular Vagus Nerve Stimulation (ta-VNS)

Sham Transcutaneous Auricular Vagus Nerve Stimulation DEVICE

Use of a sham Parasym device that mimics active stimulation but delivers only a brief, low-level output at session onset before ramping down to zero for the remainder of the 30-minute session. Administered daily for 60 days to maintain participant blinding.

Sham Transcutaneous Auricular Vagus Nerve Stimulation

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Referred to the WVU Department of Gastroenterology and Hepatology
• Diagnosis of IBS-C

You may not qualify if:

• Failure of second-line therapy with secretagogues (linaclotide, lubiprostone, plecanatide, or tenapanor)
• Failure of third-line therapy with tegaserod
• Known debilitating psychiatric illness
• Cognitive impairment
• Pregnancy
• Prisoners
• Active substance use disorder
• Concurrent opioid use
• History of major gastrointestinal surgery resulting in luminal alteration
• History of vagotomy
• Secondary causes of constipation (e.g., opioid use, uncontrolled hypothyroidism, celiac disease)

Sponsors & Collaborators

• West Virginia University: lead

Study Sites (1)

West Virginia University- Gastroenterology and Hepatology

Morgantown, West Virginia, 26506, United States

Location

Related Publications (7)

• Hou L, Rong P, Yang Y, Fang J, Wang J, Wang Y, Zhang J, Zhang S, Zhang Z, Chen JDZ, Wei W. Auricular Vagus Nerve Stimulation Improves Visceral Hypersensitivity and Gastric Motility and Depression-like Behaviors via Vago-Vagal Pathway in a Rat Model of Functional Dyspepsia. Brain Sci. 2023 Feb 1;13(2):253. doi: 10.3390/brainsci13020253.

  PMID: 36831796 BACKGROUND

• Zhu Y, Xu F, Sun C, Xu W, Li M, Gong Y, Rong P, Lin L, Chen JDZ. Noninvasive Transcutaneous Auricular Vagal Nerve Stimulation Improves Gastric Slow Waves Impaired by Cold Stress in Healthy Subjects. Neuromodulation. 2023 Dec;26(8):1851-1857. doi: 10.1016/j.neurom.2022.03.010. Epub 2022 May 19.

  PMID: 35597733 BACKGROUND

• Liu J, Lv C, Yin M, Zhu M, Wang B, Tian J, Hashimoto K, Yu Y. Efficacy and Safety of Transcutaneous Auricular Vagus Nerve Stimulation in Patients With Constipation-Predominant Irritable Bowel Syndrome: A Single-Center, Single-Blind, Randomized Controlled Trial. Am J Gastroenterol. 2024 Dec 17;120(9):2139-2153. doi: 10.14309/ajg.0000000000003257.

  PMID: 39689011 BACKGROUND

• Weronika Górska and Mikołaj Raszek, Auricular versus Cervical Vagus Nerve Stimulation: A Narrative Perspective on Safety, Mechanisms, and Clinical Applicability. MAR Neurology, Neurosurgery & Psychology, 2025. 9(4).

  BACKGROUND

• Shi X, Hu Y, Zhang B, Li W, Chen JD, Liu F. Ameliorating effects and mechanisms of transcutaneous auricular vagal nerve stimulation on abdominal pain and constipation. JCI Insight. 2021 Jul 22;6(14):e150052. doi: 10.1172/jci.insight.150052.

  PMID: 34138761 BACKGROUND

• Kovacic K, Hainsworth K, Sood M, Chelimsky G, Unteutsch R, Nugent M, Simpson P, Miranda A. Neurostimulation for abdominal pain-related functional gastrointestinal disorders in adolescents: a randomised, double-blind, sham-controlled trial. Lancet Gastroenterol Hepatol. 2017 Oct;2(10):727-737. doi: 10.1016/S2468-1253(17)30253-4. Epub 2017 Aug 18.

  PMID: 28826627 BACKGROUND

• Almario CV, Sharabi E, Chey WD, Lauzon M, Higgins CS, Spiegel BMR. Prevalence and Burden of Illness of Rome IV Irritable Bowel Syndrome in the United States: Results From a Nationwide Cross-Sectional Study. Gastroenterology. 2023 Dec;165(6):1475-1487. doi: 10.1053/j.gastro.2023.08.010. Epub 2023 Aug 16.

  PMID: 37595647 BACKGROUND

MeSH Terms

Conditions

Irritable Bowel Syndrome

Condition Hierarchy (Ancestors)

Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases

Central Study Contacts

Zain Sobani, MD

CONTACT

304-598-6200; zain.sobani@hsc.wvu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: June 17, 2026
• First Posted: June 23, 2026
• Study Start: July 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): July 1, 2027
• Last Updated: June 23, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)