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Completed

NCT Number: NCT03729271

Hydrogen Breath Test an Instrument to Predict Rifaximin-Response in Irritable Bowel Syndrome Predominant Diarrhea

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.

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Key information

Conditions

Irritable Bowel Syndrome Colonic Diseases Colonic Diseases, Functional Digestive System Diseases Gastrointestinal Diseases Intestinal Diseases Irritable Bowel Syndrome With Diarrhea

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of Michigan

Ann Arbor, Michigan, 48109, United States

About this study

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.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • 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

Exclusion criteria

  • 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
  • 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

Treatment and study plan

Rifaximin

Drug

Rifaximin will be given during weeks 2-4

Other names: Xifaxan

Glucose and lactulose hydrogen breath testing

Device

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.

Primary outcomes

  1. 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

Secondary outcomes

  1. Severity of abdominal pain by numeric rating scale (0-10)

    Time frame: baseline (week 1), up to 12 weeks

    A responder is defined as a patient with ≥30% decrease from baseline in mean weekly worst pain.

  2. Stool consistency by Bristol Stool Form Scale (1-7)

    Time frame: baseline (week 1), up to 12 weeks

    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.

  3. Severity of bloating by numeric rating scale (0-10)

    Time frame: baseline (week 1), up to 12 weeks

    A responder is defined as a patient with ≥ 30 % decrease from baseline in mean weekly worst bloating score.

  4. Severity of bowel urgency by rating scale (0-10)

    Time frame: baseline (week 1), up to 12 weeks

    A responder is defined as a patient with ≥ 30 % decrease from baseline in mean weekly worst urgency score.

  5. 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- 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.

  6. Irritable Bowel Syndrome - Quality of Life Measure responder

    Time frame: baseline (week 1), up to 12 weeks

    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.

  7. Compare the predictive value of a pre-treatment glucose or lactulose hydrogen breath test

    Time frame: first 4 weeks after rifaximin treatment

    We will compare the proportion of patients meeting the primary response definition stratified by positive or negative glucose or lactulose breath test results

Sponsors and collaborators

Lead sponsor

University of Michigan

Other

Collaborators

  • Commonwealth Diagnostics International, Inc.

Registry information

Official study title

The Role of Breath Testing in Enriching the Likelihood of Response to Rifaximin in Patients With Diarrhea IBS

Important dates

Study start
2020
Primary completion
2026
Study completion
2026
First posted
Nov 2, 2018
Registry last updated
Jan 12, 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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