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NCT Number: NCT07662083

Trans Auricular Vagal Nerve Stimulation in Patients With IBS-C

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.

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Key information

Conditions

Irritable Bowel Syndrome (IBS-C) Colonic Diseases Colonic Diseases, Functional Digestive System Diseases Gastrointestinal Diseases Intestinal Diseases Irritable Bowel Syndrome

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

West Virginia University- Gastroenterology and Hepatology

Morgantown, West Virginia, 26506, United States

Location contact

Zain Sobani, MD

CONTACT

[email protected]

304-598-6200

Zain Sobani, MD

PRINCIPAL_INVESTIGATOR

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

  • 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)

Treatment and study plan

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.

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.

Primary outcomes

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

    Time frame: Baseline to 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.

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

    Time frame: Baseline to 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.

Secondary outcomes

  1. Incidence of Adverse Events

    Time frame: Baseline through Day 60

    Evaluate the safety of ta-VNS in patients with IBS-C by assessing the incidence of adverse events during the 60-day intervention period.

  2. Participant Compliance With ta-VNS Intervention

    Time frame: Baseline to Day 60

    Assess participant compliance with the ta-VNS intervention by measuring the number of days the device was used according to the study protocol over the 60-day intervention period.

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

    Time frame: Baseline to Day 60

    Evaluate the impact of transcutaneous auricular vagus nerve stimulation (ta-VNS) in patients with IBS-C using the IBS Quality of Life (IBS-QOL) questionnaire domain scores. The IBS-QOL is a validated instrument that includes the following domains: dysphoria, interference with activity, body image, health worry, food avoidance, social reaction, and relationships. Each domain score is transformed to a 0 to 100 scale, with higher scores indicating better quality of life. The outcome measure is defined as the change in each domain score from baseline to Day 60.

Study contacts

Contact information is provided by the study sponsor or research team.

Zain Sobani, MD

CONTACT

[email protected]

304-598-6200

Sponsors and collaborators

Lead sponsor

West Virginia University

Other

Registry information

Official study title

Randomized Controlled Trial Evaluating Trans Auricular Vagal Nerve Stimulation in Patients With Irritable Bowel Syndrome Constipation Subtype

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Jun 23, 2026
Registry last updated
Jun 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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