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Disorders of Gut Brain InteractionNCT07817706

Development of a Noninvasive Metric to Measure Small Bowel Sensation - The Small Intestine Stress Test

A study testing Mannitol Solution 76 mOsm/L, Mannitol Solution 189 mOsm/L and Mannitol Solution 325 mOsm/L in people with Disorders of Gut Brain Interaction, run by Mayo Clinic at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The purpose of this research is to identify the concentration of mannitol solution (a type of sugar alcohol) that will generate a range of symptoms in individuals without Disorders of Gut Brain Interaction (DGBI) to establish the normative range of responses to small bowel (SB) distension. Read more about this study

Who is it for?
Ages 18 to 75 yearsHealthy volunteers can take part
Conditions the study is for
Disorders of Gut Brain Interaction
What is being tested?
Mannitol Solution 76 mOsm/L, Mannitol Solution 189 mOsm/L and Mannitol Solution 325 mOsm/L
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
20 participants
Where
1 siteUnited States
Study dates
1 Sep 2026to 30 Dec 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

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 75 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • No current gastrointestinal symptoms
  • No prior history of GI disorders, in particular DGBIs
  • Ability to provide informed consent
  • Ability to participate in study procedures
  • Absence of other diseases (structural or metabolic) which could interfere with interpretation of the study results
  • For females, must not be pregnant or lactating due to radiation exposure.
  • Stable doses of thyroid replacement, estrogen replacement, low-dose aspirin for cardioprotection, and birth control are permissible.

Who cannot join

  • Subjects on any medications that impact transit or integrity of small bowel mucosal barrier (e.g. chronic NSAIDS) of the GI tract will be excluded.
  • Patients with prior bowel surgery (not including appendectomy and cholecystectomy)
  • Patients who may have altered sensation (central sensitization or conditions that may induce bowel hyperalgesia) based on PI review of medical history (ie, fibromyalgia, endometriosis, chronic pelvic pain)

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

United States1 site, 1 recruiting
  • Mayo Clinic

    Rochester, Minnesota, 55905

    Taylor Hines, 507-538-9959

    Recruiting

Other trials in United States

About this study

The purpose of this research is to identify the concentration of mannitol solution (a type of sugar alcohol) that will generate a range of symptoms in individuals without Disorders of Gut Brain Interaction (DGBI) to establish the normative range of responses to small bowel (SB) distension.

Being tested
Mannitol Solution 76 mOsm/L, Mannitol Solution 189 mOsm/L, Mannitol Solution 325 mOsm/L, Scintigraphy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Mannitol Solution 76 mOsm/LDrug

    Participants will ingest 500 mL of mannitol solution at 76 mOsm/L radiolabeled with 111Indium-DTPA during one testing visit.

  • Mannitol Solution 189 mOsm/LDrug

    Participants will ingest 500 mL of mannitol solution at 189 mOsm/L radiolabeled with 111Indium-DTPA during one testing visit.

  • Mannitol Solution 325 mOsm/LDrug

    Participants will ingest 500 mL of mannitol solution at 325 mOsm/L radiolabeled with 111Indium-DTPA during one testing visit.

  • ScintigraphyDiagnostic test

    Scintigraphy will be used to track gastric emptying, small bowel transit, and colonic filling of the radiolabeled mannitol solution during each testing visit.

Study groups in NCT07817706
Study groupRoleWhat they receive
Healthy Volunteers Receiving Mannitol SolutionsExperimentalHealthy adult volunteers will receive all three mannitol solution osmolarities-76 milliosmol (mOsm/L), 189 mOsm/L, and 325 mOsm/L-on three separate testing occasions spaced at least 5 days apart. Each solution will be administered orally as 500 mL radiolabeled with Pentetate Indium Disodium In-111 (111Indium-DTPA).
Receives: Drug: Mannitol Solution 76 mOsm/L; Drug: Mannitol Solution 189 mOsm/L; Drug: Mannitol Solution 325 mOsm/L; Diagnostic Test: Scintigraphy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Peak Gastrointestinal Symptom Severity During Small Bowel Transit Following 76 mOsm/L Mannitol Solution Ingestion

    Peak gastrointestinal symptom severity will be assessed using a 7-point Likert symptom scale after ingestion of radiolabeled mannitol solution. Symptoms assessed include abdominal pain or discomfort, nausea, bloating, distension, borborygmi, diarrhea, urgency, and related gastrointestinal symptoms. The peak symptom score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. Scores range from 1 to 7, with higher scores indicating greater symptom severity.

    Measured: At baseline and at 15-minute intervals beginning 30 minutes after ingestion through 180 minutes post-ingestion.

  2. Peak Gastrointestinal Symptom Severity During Small Bowel Transit Following 189 mOsm/L Mannitol Solution Ingestion

    Peak gastrointestinal symptom severity will be assessed using a 7-point Likert symptom scale after ingestion of radiolabeled mannitol solution. Symptoms assessed include abdominal pain or discomfort, nausea, bloating, distension, borborygmi, diarrhea, urgency, and related gastrointestinal symptoms. The peak symptom score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. Scores range from 1 to 7, with higher scores indicating greater symptom severity.

    Measured: At baseline and at 15-minute intervals beginning 30 minutes after ingestion through 180 minutes post-ingestion.

  3. Peak Gastrointestinal Symptom Severity During Small Bowel Transit Following 325 mOsm/L Mannitol Solution Ingestion

    Peak gastrointestinal symptom severity will be assessed using a 7-point Likert symptom scale after ingestion of radiolabeled mannitol solution. Symptoms assessed include abdominal pain or discomfort, nausea, bloating, distension, borborygmi, diarrhea, urgency, and related gastrointestinal symptoms. The peak symptom score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. Scores range from 1 to 7, with higher scores indicating greater symptom severity.

    Measured: At baseline and at 15-minute intervals beginning 30 minutes after ingestion through 180 minutes post-ingestion.

Secondary outcomes (9)
  1. Peak Abdominal Pain Intensity Following 76 mOsm/L Mannitol Solution

    Peak abdominal pain intensity will be assessed after ingestion of 500 mL radiolabeled 76 mOsm/L mannitol solution using the Kohn Reactivity Scale. The peak pain intensity score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. The total score ranges from 24 to 120. Higher scores indicate greater pain intensity

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  2. Peak Abdominal Pain Intensity Following 189 mOsm/L Mannitol Solution

    Peak abdominal pain intensity will be assessed after ingestion of 500 mL radiolabeled 189 mOsm/L mannitol solution using the Kohn Reactivity Scale. The peak pain intensity score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. The total score ranges from 24 to 120. Higher scores indicate greater pain intensity

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  3. Peak Abdominal Pain Intensity Following 325 mOsm/L Mannitol Solution

    Peak abdominal pain intensity will be assessed after ingestion of 500 mL radiolabeled 325 mOsm/L mannitol solution using the Kohn Reactivity Scale. The peak pain intensity score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. The total score ranges from 24 to 120. Higher scores indicate greater pain intensity

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  4. Peak Abdominal Pain Unpleasantness Following 76 mOsm/L Mannitol Solution

    Peak abdominal pain unpleasantness will be assessed after ingestion of 500 mL radiolabeled 76 mOsm/L mannitol solution using the Kohn Reactivity Scale. The peak pain unpleasantness score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. The total score ranges from 24 to 120. Higher scores indicate greater levels of pain unpleasantness.

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  5. Peak Abdominal Pain Unpleasantness Following 189 mOsm/L Mannitol Solution

    Peak abdominal pain unpleasantness will be assessed after ingestion of 500 mL radiolabeled 189 mOsm/L mannitol solution using the Kohn Reactivity Scale. The peak pain unpleasantness score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. The total score ranges from 24 to 120. Higher scores indicate greater levels of pain unpleasantness.

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  6. Peak Abdominal Pain Unpleasantness Following 325 mOsm/L Mannitol Solution

    Peak abdominal pain unpleasantness will be assessed after ingestion of 500 mL radiolabeled 325 mOsm/L mannitol solution using the Kohn Reactivity Scale. The peak pain unpleasantness score observed during the small bowel phase will be identified. The small bowel phase is defined as the period during which scintigraphy confirms radiolabeled solution in the small bowel and before more than 25% of tracer has reached the ascending colon. The total score ranges from 24 to 120. Higher scores indicate greater levels of pain unpleasantness.

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  7. Change in Gastrointestinal Symptom Severity Following 76 mOsm/L Mannitol Solution

    Gastrointestinal symptom severity will be assessed after ingestion of 500 mL radiolabeled 76 mOsm/L mannitol solution using a modified Gastric Symptom Severity Scale. Symptoms assessed include abdominal pain or discomfort, nausea, bloating, distension, borborygmi, diarrhea, loose stools, urgency, and related gastrointestinal symptoms. Scores range from 1 to 7, with higher scores indicating greater symptom severity.

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  8. Change in Gastrointestinal Symptom Severity Following 189 mOsm/L Mannitol Solution

    Gastrointestinal symptom severity will be assessed after ingestion of 500 mL radiolabeled 189 mOsm/L mannitol solution using a modified Gastric Symptom Severity Scale. Symptoms assessed include abdominal pain or discomfort, nausea, bloating, distension, borborygmi, diarrhea, loose stools, urgency, and related gastrointestinal symptoms. Scores range from 1 to 7, with higher scores indicating greater symptom severity.

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

  9. Change in Gastrointestinal Symptom Severity Following 325 mOsm/L Mannitol Solution

    Gastrointestinal symptom severity will be assessed after ingestion of 500 mL radiolabeled 325 mOsm/L mannitol solution using a modified Gastric Symptom Severity Scale. Symptoms assessed include abdominal pain or discomfort, nausea, bloating, distension, borborygmi, diarrhea, loose stools, urgency, and related gastrointestinal symptoms. Scores range from 1 to 7, with higher scores indicating greater symptom severity.

    Measured: Baseline, then every 15 minutes from 30 minutes through 180 minutes after ingestion

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 Sep 2026
  2. Study start1 Sep 2026
  3. Primary completion30 Jun 2027 (estimated)
  4. Study completion30 Dec 2027 (estimated)

Resources

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 N/A
Primary purpose
Diagnosis
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07817706
Sponsor's protocol ID
25-013906
Status last verified
Sep 2026
First submitted
8 Sep 2026
Last updated
2 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Mannitol Solution 76 mOsm/L, Mannitol Solution 189 mOsm/L and Mannitol Solution 325 mOsm/L in people with Disorders of Gut Brain Interaction, run by Mayo Clinic 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 7 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 2 Oct 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.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Taylor Hines (507-538-9959, hines.taylor@mayo.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Peak Gastrointestinal Symptom Severity During Small Bowel Transit Following 76 mOsm/L Mannitol Solution Ingestion (time frame: At baseline and at 15-minute intervals beginning 30 minutes after ingestion through 180 minutes post-ingestion.). The study lists 3 primary outcomes in all. 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 2 Oct 2026.

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