Irritable Bowel SyndromePhase 4NCT03729271
Hydrogen Breath Test an Instrument to Predict Rifaximin-Response in Irritable Bowel Syndrome Predominant Diarrhea
A Phase 4 study testing Rifaximin and Glucose and lactulose hydrogen breath testing in people with Irritable Bowel Syndrome and Irritable Bowel Syndrome With Diarrhea, run by University of Michigan at 1 site in United States.
Trial summary
The purpose of this study is to learn more about how to improve treatment of patients with diarrhea predominant Irritable Bowel Syndrome (IBS-D) symptoms.Included patients will be requested to answer online surveys and will undergo treatment with rifaximin. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Irritable Bowel Syndrome, Irritable Bowel Syndrome With Diarrhea
- What is being tested?
- Rifaximin and Glucose and lactulose hydrogen breath testing
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 148 participants
- Where
- 1 siteUnited States
- Study dates
- 9 Jan 2020to 1 Jan 2026
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- IBS-D (Rome IV Diagnostic Criteria)
- Diary compliance for at least 5 days and no rescue medications during baseline
- Appropriate levels of abdominal pain and diarrhea
Who cannot join
- Pregnant women or planning on becoming pregnant while in the study, or lactating women while in the study
- Inflammatory bowel disease, diabetes mellitus, systemic sclerosis, or celiac disease
- Active gastrointestinal or hematological malignancy which requires ongoing treatment
- Surgery to the GI tract in the past 3 months
- Gastrointestinal infection or diverticulitis in the past 3 months
- Severe hepatic impairment
Show all 11Show fewer
- Any use of antibiotics in the past month
- Current use of probiotics
- Any history of allergies to rifaximin or its derivatives
- Any comitant use of P-glycoprotein inhibitors (for example. Cyclosporine)
- Known allergies to glucose or lactulose
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Role of Breath Testing in Enriching the Likelihood of Response to Rifaximin in Patients With Diarrhea IBS
The purpose of this study is to learn more about how to improve treatment of patients with diarrhea predominant Irritable Bowel Syndrome (IBS-D) symptoms.Included patients will be requested to answer online surveys and will undergo treatment with rifaximin. Hydrogen breath testing and biologic samples collection will also be completed during the study.
Read the detailed description
The study aims to determine whether hydrogen breath testing can be used to identify patients with IBS-D who are more likely to respond to rifaximin. Participating patients will complete a one week screening period when brief daily survey will be answered. Eligible patients will proceed with the treatment phase of the study, when patients will receive a 14 day course of rifaximin. All included patients will complete glucose and lactulose hydrogen breath tests before and after rifaximin treatment. Biological samples (e.g. blood, stool) will be collected at pre-determined time points and patients will answer daily brief survey for the duration of the study.
It is anticipated that 210 patients will be screened to reach a goal of enrolling 175 patients for the treatment phase of the study.
- Being tested
- Rifaximin, Glucose and lactulose hydrogen breath testing
- Keywords
- IBS, Irritable Bowel Syndrome
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RifaximinDrug
Also called Xifaxan
Rifaximin will be given during weeks 2-4
Glucose and lactulose hydrogen breath testingDevice
Subjects will undergo glucose and lactulose hydrogen breath tests for Small Intestinal Bacterial Overgrowth (SIBO) on consecutive days using a commercially available home base kits (Glucose Hydrogen Breath Test Collection Kit and Lactulose Hydrogen Breath Test Collection Kit for SIBO from Commonwealth Diagnostic International) prior to Rifaximin treatment and at week 13 of the study.
| Study group | Role | What they receive |
|---|---|---|
| Rifaximin and breath tests | Experimental | Rifaximin 550mg three times a day for 14 days. Breath tests (glucose and lactulose) will be completed prior to Rifaximin treatment and at week 13 of the study. Receives: Drug: Rifaximin; Device: Glucose and lactulose hydrogen breath testing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of treatment responders
A responder is defined as a patient simultaneously meeting weekly response criteria for abdominal pain (≥30% decrease from baseline in mean weekly pain score) and stool consistency (≥50% decrease from baseline in number of days/week with Bristol Stool Scale type 6 or 7 stool) during ≥2 of the 4 weeks after treatment
Measured: first 4 weeks after rifaximin treatment
Secondary outcomes (7)
Severity of abdominal pain by numeric rating scale (0-10)
A responder is defined as a patient with ≥30% decrease from baseline in mean weekly worst pain.
Measured: baseline (week 1), up to 12 weeks
Stool consistency by Bristol Stool Form Scale (1-7)
A responder is defined as a patient with ≥ 50% decrease from baseline in number of days/weeks with Bristol stool scale type 6 or 7 stool.
Measured: baseline (week 1), up to 12 weeks
Severity of bloating by numeric rating scale (0-10)
A responder is defined as a patient with ≥ 30 % decrease from baseline in mean weekly worst bloating score.
Measured: baseline (week 1), up to 12 weeks
Severity of bowel urgency by rating scale (0-10)
A responder is defined as a patient with ≥ 30 % decrease from baseline in mean weekly worst urgency score.
Measured: baseline (week 1), up to 12 weeks
Compare the predictive value of a pre-treatment glucose vs. lactulose hydrogen breath test for symptomatic response to rifaximin in IBS-D patients.
Irritable Bowel Syndrome- Severity Scoring system (IBS-SSS) responder decrease in score of >75 points compared to baseline. The scoring range is from 0% to 500% with decreasing points indicating improvements in symptoms. Scores will be compared week 1 to those collected on weeks 4, 8, and 12.
Measured: baseline (week 1), up to 12 weeks
Irritable Bowel Syndrome - Quality of Life Measure responder
Defined as a decrease in score of 14 points from the baseline assessment. The score range is from 34 to 170, with decreasing in score indicating improvement in symptoms. Scores will be compared week 1 to those collected on weeks 4, 8, and 12.
Measured: baseline (week 1), up to 12 weeks
Compare the predictive value of a pre-treatment glucose or lactulose hydrogen breath test
We will compare the proportion of patients meeting the primary response definition stratified by positive or negative glucose or lactulose breath test results
Measured: first 4 weeks after rifaximin treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2018
- Study start9 Jan 2020
- Primary completion1 Jan 2026
- Study completion1 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel SyndromeStudies of the same condition, open and under way.
- More trials run by University of MichiganThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 148 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Collaborators
- Commonwealth Diagnostics International, Inc.
- Responsible party
- Principal investigator, William Chey, University of Michigan
- Investigators
- William Chey, M.D., Principal investigator, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03729271
- Sponsor's protocol ID
- HUM00142925
- Status last verified
- Feb 2025
- First submitted
- 10 Oct 2018
- Last updated
- 12 Jan 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 12 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Breath Testing in Enriching the Likelihood of Response to Rifaximin in Patients With Diarrhea IBS
- ClinicalTrials.gov ID
- NCT03729271
- Acronym / sponsor ID
- HUM00142925
- Keywords
- IBS, Irritable Bowel Syndrome
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 148 participants (actual)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Collaborators
- Commonwealth Diagnostics International, Inc.
- Study start
- 9 Jan 2020 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 1 Jan 2026 (actual)
- First posted
- 2 Nov 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to learn more about how to improve treatment of patients with diarrhea predominant Irritable Bowel Syndrome (IBS-D) symptoms.Included patients will be requested to answer online surveys and will undergo treatment with rifaximin. Hydrogen breath testing and biologic samples collection will also be completed during the study.
Detailed description
The study aims to determine whether hydrogen breath testing can be used to identify patients with IBS-D who are more likely to respond to rifaximin. Participating patients will complete a one week screening period when brief daily survey will be answered. Eligible patients will proceed with the treatment phase of the study, when patients will receive a 14 day course of rifaximin. All included patients will complete glucose and lactulose hydrogen breath tests before and after rifaximin treatment. Biological samples (e.g. blood, stool) will be collected at pre-determined time points and patients will answer daily brief survey for the duration of the study.
It is anticipated that 210 patients will be screened to reach a goal of enrolling 175 patients for the treatment phase of the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Rifaximin and breath tests | Experimental | Drug: Rifaximin, Device: Glucose and lactulose hydrogen breath testingRifaximin 550mg three times a day for 14 days. Breath tests (glucose and lactulose) will be completed prior to Rifaximin treatment and at week 13 of the study. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- IBS-D (Rome IV Diagnostic Criteria)
- Diary compliance for at least 5 days and no rescue medications during baseline
- Appropriate levels of abdominal pain and diarrhea
Key exclusion criteria (11 listed)
- Pregnant women or planning on becoming pregnant while in the study, or lactating women while in the study
- Inflammatory bowel disease, diabetes mellitus, systemic sclerosis, or celiac disease
- Active gastrointestinal or hematological malignancy which requires ongoing treatment
- Surgery to the GI tract in the past 3 months
- Gastrointestinal infection or diverticulitis in the past 3 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RifaximinAlso: XifaxanRifaximin will be given during weeks 2-4 | Drug | Rifaximin and breath tests |
| Glucose and lactulose hydrogen breath testingSubjects will undergo glucose and lactulose hydrogen breath tests for Small Intestinal Bacterial Overgrowth (SIBO) on consecutive days using a commercially available home base kits (Glucose Hydrogen Breath Test Collection Kit and Lactulose Hydrogen Breath Test Collection Kit for SIBO from Commonwealth Diagnostic International) prior to Rifaximin treatment and at week 13 of the study. | Device | Rifaximin and breath tests |
Primary outcome
Number of treatment responders
Time frame: first 4 weeks after rifaximin treatment
A responder is defined as a patient simultaneously meeting weekly response criteria for abdominal pain (≥30% decrease from baseline in mean weekly pain score) and stool consistency (≥50% decrease from baseline in number of days/week with Bristol Stool Scale type 6 or 7 stool) during ≥2 of the 4 weeks after treatment
7 secondary outcomes
Severity of abdominal pain by numeric rating scale (0-10)
Time frame: baseline (week 1), up to 12 weeks
Stool consistency by Bristol Stool Form Scale (1-7)
Time frame: baseline (week 1), up to 12 weeks
Severity of bloating by numeric rating scale (0-10)
Time frame: baseline (week 1), up to 12 weeks
Severity of bowel urgency by rating scale (0-10)
Time frame: baseline (week 1), up to 12 weeks
Compare the predictive value of a pre-treatment glucose vs. lactulose hydrogen breath test for symptomatic response to rifaximin in IBS-D patients.
Time frame: baseline (week 1), up to 12 weeks
Irritable Bowel Syndrome - Quality of Life Measure responder
Time frame: baseline (week 1), up to 12 weeks
Compare the predictive value of a pre-treatment glucose or lactulose hydrogen breath test
Time frame: first 4 weeks after rifaximin treatment
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jan 2026.
Related trials for Irritable Bowel Syndrome
RecruitingObservational study
Abdominal Symptoms and Rosacea: An Observational Study on the Association Between Irritable Bowel Syndrome (IBS) and the Gut-Skin Axis
IBS (Irritable Bowel Syndrome), Rosacea
Recruiting
Stress Reduction and Lifestyle Modification in Irritable Bowel Syndrome Patients
Irritable Bowel Syndrome
Recruiting
Exercise Interventions and Dietary Advice in Fibromyalgia and IBS
Fibromyalgia, Irritable Bowel Syndrome
RecruitingPhase 2
A Study of Brenipatide (LY3537031) in Participants With Irritable Bowel Syndrome-Constipation (IBS-C)
Irritable Bowel Syndrome, Constipation
RecruitingPhase 2
A Study of Brenipatide (LY3537031) in Participants With Irritable Bowel Syndrome-Diarrhea (IBS-D)
Irritable Bowel Syndrome, Diarrhea
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
William Chey, M.D. principal investigator
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Rifaximin and Glucose and lactulose hydrogen breath testing in people with Irritable Bowel Syndrome and Irritable Bowel Syndrome With Diarrhea, run by University of Michigan at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of treatment responders (time frame: first 4 weeks after rifaximin treatment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jan 2026.