A Longitudinal Study to Identify IBS Phenotypes Using Fecal Microbiota and Hydrogen Breath Testing

NCT03219528 | Completed Phase 4 Results FDA Drug

• 2 other identifiers: HUM1294271K23DK124567
• Study Type: interventional
• Target: 74
• Locations: 1 country
• Sites: 1

Brief Summary

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a highly prevalent but poorly understood condition with limited treatment options. Current therapies, including a nonabsorbable antibiotic rifaximin or diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP), show efficacy in 50% or less of patients. In this proposal, participants with IBS-D will be randomized to receive either rifaximin or low FODMAP dietary intervention.

Conditions

Irritable Bowel Syndrome

Keywords

Irritable Bowel Syndrome; Diarrhea; Small Intestinal Bacterial Overgrowth; Gut Microbiota

Outcome Measures

Primary Outcomes (2)

• Change in Mean Daily Abdominal Pain

  Change in mean daily abdominal pain was measured using a visual analog scale (VAS) after intervention compared with baseline. VAS was a scale of 0 to 10, with higher numbers indicating a higher degree of pain; 0 indicated no pain and 10 indicated severe pain.

  Baseline, Week 5

• Change in Mean Daily Bloating

  Change in mean daily bloating was measured using a visual analog scale (VAS) after intervention compared with baseline. VAS was a scale of 0 to 10, with higher numbers indicating a higher degree of bloating; 0 indicated no bloating and 10 indicated severe bloating.

  Baseline, Week 5

Secondary Outcomes (7)

• Change in Irritable Bowel Syndrome (IBS) Symptom Severity Scale

  Baseline, Week 5

• Change in Gastrointestinal System Ratings Scale (GSRS)

  Baseline, Week 5

• Change in Stool Form

  Baseline, Week 5

• Change in Psychological Function

  Baseline, Week 5

• Change in Irritable Bowel Syndrome Quality of Life Instrument (IBS-QOL)

  Baseline, Week 5

Other Outcomes (2)

• Glucose Breath Tests

  4 weeks

• Fecal Microbiota

  4 weeks

Study Arms (2)

Rifaximin

ACTIVE COMPARATOR

Rifaximin 550 mg three times daily for 14 days

Drug: Rifaximin 550 MG

Low FODMAP Group

ACTIVE COMPARATOR

Low FODMAP diet for 4 weeks

Other: Low FODMAP Diet

Interventions

Rifaximin 550 MG DRUG

Rifaximin 550 mg three times daily for 14 days

Rifaximin

Low FODMAP Diet OTHER

Low FODMAP dietary intervention for 4 weeks

Low FODMAP Group

Eligibility Criteria

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

You may qualify if:

• Adult subjects greater than or equal to 18 years of age who meet Rome IV criteria for diarrhea-predominant irritable bowel syndrome (IBS-D).
• Prior colonoscopy or sigmoidoscopy within the past 2 years with random colon biopsies to exclude the presence of microscopic colitis.

You may not qualify if:

• Underlying celiac disease, inflammatory bowel disease, or other organic disease that could explain their symptoms.
• Subjects with a history of GI tract surgery, except for cholecystectomy or appendectomy, will also be excluded from the study.
• Women who are pregnant or breastfeeding Antibiotics taken within 3 months prior to enrollment will not be permitted. Subjects on probiotics must discontinue their use at least 1 month prior to enrollment.
• Subjects who have previously received formal dietary education for IBS, including a low FODMAP diet, or previously received antibiotics, including rifaximin, for treatment of IBS-D will be excluded from the study.

Sponsors & Collaborators

• University of Michigan: lead
• Michigan Institute for Clinical and Health Research (MICHR): collaborator
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48109, United States

Location

MeSH Terms

Conditions

Irritable Bowel Syndrome; Diarrhea

Interventions

Rifaximin; FODMAP Diet

Condition Hierarchy (Ancestors)

Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Signs and Symptoms, Digestive; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Rifamycins; Heterocyclic Compounds, 4 or More Rings; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Lactams, Macrocyclic; Macrocyclic Compounds; Polycyclic Compounds; Elimination Diets; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Results Point of Contact

• Title: Allen Lee
• Organization: University of Michigan

allenlee@med.umich.edu

734-936-4785

Study Officials

• Allen Lee, MD

  University of Michigan

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: July 13, 2017
• First Posted: July 17, 2017
• Study Start: February 13, 2018
• Primary Completion: February 28, 2024
• Study Completion: February 28, 2024
• Last Updated: April 27, 2025
• Results First Posted: April 27, 2025

Record last verified: 2025-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)