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Neck nerve stimulation device for stress responses in irritable bowel syndrome

Tests a handheld neck stimulator against usual care in adults with irritable bowel syndrome.

Key facts

Who runs it
University of California, Los Angeles
Where
Los Angeles, United StatesSee the site
Trial code
Registry title
Effects of nVNS on Stress Reactivity in IBS
Status
Not yet recruiting
People taking part
200 people, planned
Starts
1 Dec 2026
Expected to end
1 Dec 2031
Type of study
Interventional, 2 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • Truvaga Plus
Record updated
9 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with at least moderate irritable bowel syndrome (IBS) with diarrhea or mixed bowel habits. People are randomly put into a group that uses a handheld neck nerve-stimulation device at home for 8 weeks, or a usual care group.

Age
18 to 50 years
Sex
All sexes can join. Women must not have reached menopause and must have generally regular periods.
Disease stage
IBS-D or IBS-M by Rome V criteria, at least moderate severity (IBS-SSS ≥175).
Earlier treatment
No hormonal medicines, including birth control or hormone replacement therapy, now or in the last 3 months. No plan to start a new IBS treatment during the 8-week study period.

Main reasons for not taking part

  • Obesity (BMI > 30), pregnancy, or being in or past menopause.
  • Another bowel disease that could explain the symptoms, such as inflammatory bowel disease or celiac disease.
  • Any implanted electrical device, metal near the neck, or anything that makes MRI unsafe.
  • Heart disease, heart attack within 5 years, or significant blood pressure or heart rate problems.
  • Past abdominal surgery other than appendix, gallbladder, benign polyp removal, or hiatus hernia.

The registry criteria, word for word

Show all 25 criteriaShow less

Who can take part

  • Age 18-50 years
  • Meets Rome V diagnostic criteria for IBS-D or IBS-M
  • At least moderate IBS symptom severity, defined as IBS-SSS ≥175
  • For females: premenopausal with generally regular menstrual cycles and willing to complete study visits within the study-specified menstrual-cycle window when feasible
  • Able to understand and provide informed consent in English
  • Willing and able to complete questionnaires, biospecimen collection, wearable monitoring, MRI procedures, and randomized study requirements

Who cannot take part

  • Evidence or history of another gastrointestinal disease that could explain symptoms, including inflammatory bowel disease or celiac disease, unless adequately excluded by clinical evaluation or prior testing
  • Previous use in the last 3 months OR current use of hormonal medications, including hormonal contraceptives (i.e. birth control pills, patches, implants, or intrauterine devices (IUDs)) or hormone replacement therapy
  • MRI contraindication, including a non-removable ferromagnetic implant or device, prior significant tattoo-related heating or burns, severe claustrophobia that cannot be managed, or another condition judged unsafe for MRI
  • Past abdominal surgery (except for appendectomy, cholecystectomy, benign polypectomy, hiatus hernia)
  • Major active psychiatric illness (e.g., schizophrenia, bipolar disorder), significant neurologic or central nervous system disease, or another medical condition that could affect safety, adherence, or interpretation of study outcomes
  • Dermatologic conditions affecting the neck region that would interfere with nVNS placement
  • History of cervical vagotomy
  • Movement disorder
  • Clinically significant hypertension, hypotension, bradycardia, or tachycardia
  • Cardiac disease or atherosclerotic cardiac disease, including congestive heart failure, known severe coronary artery disease, or recent myocardial infarction within 5 years
  • Individuals with obesity (BMI > 30)
  • Pregnancy or a positive pregnancy test
  • Perimenopausal or postmenopausal status
  • Current participation in another IBS-specific intervention study or planned initiation of a new IBS-directed treatment during the 8-week randomized period
  • Contraindication to cervical nVNS or inability to use the device safely
  • Any implanted electrical device
  • Any metallic device implanted at or near the neck
  • Use of another electrical device at the same time (e.g., TENS unit, muscle stimulator) or any portable electronic device
  • Inability or unwillingness to provide informed consent or complete study procedures in English

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 50 years old?

Where in United States

  • University of California, Los AngelesLos Angeles, United StatesContact: Michelle ChoyNot yet recruiting

About the trial

What the trial wants to find out

Irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction that causes abdominal pain and altered bowel habits. Many people with IBS also experience symptoms outside the bowel, such as headaches, widespread pain, poor sleep, anxiety, and depression; these symptoms are especially common in females. This study focuses on stress reactivity (SR), a persistent pattern of stress-system activity that may be linked to autonomic nervous system function, immune activity, the gut microbiome, and brain processing. The investigators will enroll adults with at least moderate IBS symptoms and randomly assign them to 8 weeks of non-invasive vagal nerve stimulation (nVNS) or Usual Care. Participants assigned to nVNS will use a handheld device on the left side of the neck at home twice daily. The investigators will compare changes in IBS severity and other physical symptoms and examine whether baseline or treatment-related changes in blood, stool, heart-rate variability, sex hormones, and brain imaging measures are associated with response. The study will also explore whether treatment effects and predictors differ by sex.

The 2 groups in the trial

  • nVNSExisting treatment, for comparison

    Device: Participants will self-administer a transcutaneous cervical nVNS device, Truvaga Plus, which is identical to GammaCore but is rechargeable. Truvaga Plus is classified as a general wellness product that does not require FDA clearance and can be purchased without a prescription (electroCore LLC, Basking Ridge, NJ, USA, letter of support). Usage: The nVNS will be delivered via two stainless steel contact surfaces that are coated with conductive gel before each treatment. The device will be positioned in parallel with the carotid pulse on the left side of the neck. Two back-to-back 2-minute nVNS stimulations (4 minutes total) will be administered twice daily at home for 8 weeks. Intensity: Level is dependent on the patient. They will be instructed to increase the intensity until they feel a strong but comfortable sensation-tingling or a slight lip pull is common. Most users find the ideal intensity between levels 4 and Frequency: 2 sessions, 2x daily; 224 sessions total

    Treatment: Truvaga Plus

  • Usual careNo study treatment, for comparison

    Participants assigned to the Usual Care arm will undergo the same assessments as those in the nVNS arm but will not receive any specific intervention from the project. No restrictions will be placed on participants, except that they will be asked not to start any new therapies for IBS or any new medicines unless deemed necessary by their healthcare provider.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Effects of Non-invasive Vagal Nerve Stimulation on Clinical, Peripheral Biologic, and Brain Measures of Stress Reactivity in Irritable Bowel Syndrome: a Randomized Controlled Trial
Plain-language title
Neck nerve stimulation device for stress responses in irritable bowel syndromeGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 14 November 2026.
Fit questions
Built from NCT07926945, who can take part
Record updated
9 November 2026