Novel Pilot Study to Treat Symptoms of IBS with Diarrhea Using Combination Therapy of a Low-FODMAP Diet and a Neuromodulator

Last updated: January 19, 2025
Sponsor: Mayo Clinic
Overall Status: Active - Recruiting

Phase

1

Condition

Stomach Discomfort

Bowel Dysfunction

Lactose Intolerance

Treatment

Mirtazapine

Placebo

Clinical Study ID

NCT06684470
23-011874
  • Ages 18-70
  • All Genders

Study Summary

The purpose of this research is to study the added benefit of treating IBS symptoms with a medication called mirtazapine in treating IBS symptoms when paired with a low-FODMAP diet compared to a low-FODMAP diet alone. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are short-chain carbohydrates that can cause digestive distress in some people.

You have been asked to take part in this research because you have symptoms of diarrhea-predominant irritable bowel syndrome that may respond to treatment with a combination of a medication called mirtazapine and a low-FODMAP diet.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Participants must meet all of the inclusion criteria to participate in this study:

  • Adults (ages 18-70)

  • Score of >175 on the IBS-SSS questionnaire

  • Must meet Rome IV criteria for IBS-D

  • If subject is of reproductive capability a negative urine pregnancy test mustbe available prior to entering the study

  • Ability to understand study procedures and to comply with them for the entirelength of the study

Exclusion

Exclusion Criteria:

  • All candidates meeting any of the below exclusion criteria at baseline will beexcluded from study participation:

  • Score of < 175 on the IBS-SSS

  • Prior diagnoses of: known celiac disease, small intestinal bacterialovergrowth, inflammatory bowel disease, or microscopic colitis

  • Ongoing significant anxiety or depression

  • A history of a known side effect to mirtazapine

  • Prior treatment with a low FODMAP diet or mirtazapine without clinical benefit

  • Active alcohol or drug abuse

  • Inability to read or understand the consent form

  • Any other medical or psychological reason that would prevent activeparticipation in a research study

  • Pregnant females

Study Design

Total Participants: 20
Treatment Group(s): 2
Primary Treatment: Mirtazapine
Phase: 1
Study Start date:
December 19, 2024
Estimated Completion Date:
December 19, 2025

Study Description

We hypothesize that adult patients with IBS-D treated with a combination of a low FODMAP diet and mirtazapine will have a greater improvement in global IBS symptoms including abdominal pain and diarrhea in addition to improved quality of life compared to those treated with a low-FODMAP diet only. Global improvement in IBS symptoms will be evaluated using the validated IBS-SSS questionnaire. We will evaluate changes in quality of life using a validated IBS-QoL questionnaire. We will assess the improvement in abdominal pain using a numerical rating system and assess improvements in diarrhea using the Bristol stool form scale. We will assess responses to bloating using a Mayo bloating questionnaire forms. We will assess improvement in diarrhea using the Bristol stool form scale.

Improvement in anxiety and any other descriptive information as provided by patients including patients reporting impression of overall severity of symptoms at the beginning, middle, and end of study.

Irritable bowel syndrome (IBS) is a common gastrointestinal (GI) disorder that affects up to 10% of the United States adult population. IBS is characterized by recurrent abdominal pain and altered bowel habits, diagnosed using the Rome IV criteria. Approximately one-third of all IBS patients are classified as having IBS with diarrhea (IBS-D), which has no validated treatment algorithm. The American College of Gastroenterology IBS guideline recommends the low-FODMAP (fermentable oligo-, di-, monosaccharide, and polyol) diet as a safe and modestly effective treatment. An analysis of 7 randomized, controlled trials found that the low-FODMAP diet was associated with an improvement in global IBS symptoms. However, despite following the low-FODMAP diet, many patients have persistent abdominal pain, which can be difficult to treat. The mechanisms underlying chronic abdominal pain in patients with IBS are unknown, although visceral and central hypersensitivity are thought to play a role. No medication is FDA-approved for the treatment of abdominal pain in IBS. Mirtazapine is an atypical antidepressant that acts on several classes of receptors. In a small open-label study mirtazapine improved IBS-D symptoms, including abdominal pain.

Connect with a study center

  • Mayo Clinic

    Jacksonville, Florida 32224
    United States

    Active - Recruiting

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