Yield of Diagnostic Tests and Effects of Crofelemer for Chronic Idiopathic Diarrhea In Non-HIV Patients

January 26, 2026 updated by: Brooks Cash, The University of Texas Health Science Center, Houston

Yield of Diagnostic Tests and Management of Crofelemer for Chronic Idiopathic Diarrhea In Non-HIV Patients: A Pilot Study

The purpose of this study is to evaluate the effectiveness of the drug Crofelemer in the treatment of non-HIV patients with chronic idiopathic diarrhea; to determine the prevalence of identifiable causes of chronic diarrhea in a non-HIV patients; to assess the diagnostic yield, in terms of identification of treatable etiologies, of commercially available diagnostic evaluations in adult, non-HIV patients with chronic idiopathic diarrhea, that is, evaluate which tests, among the standard diagnostic tests commonly conducted as part of the evaluation of chronic idiopathic diarrhea, are most likely to identify a treatable cause of the diarrhea; and to analyze the relationship between chronic idiopathic diarrhea and health-related quality of life and assess the impact of crofelemer treatment on health-related quality of life.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
93

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Texas
      • Houston, Texas, United States, 77030
        • The University of Texas Health Science Center at Houston

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years to 71 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with chronic diarrhea (defined as 3 non-bloody loose stools per day or more than 20 non-bloody loose stools per week for more ≥ 4 weeks) and Bristol Stool Form Scale for stool consistency of 6/7 with >50% stool without an obvious cause after evaluation for organic etiologies.
  • Patients from any ethnicity

Exclusion Criteria:

  • Hematochezia (potentially related to an organic cause).
  • Subjects less than 18 years of age more than 75 years of age (safety and effectiveness of crofelemer has not been established in these age groups).
  • Pregnant females (crofelemer is a Category C drug due to lack of well-controlled studies to study its effects in this population).
  • Lactating females (it is unknown if crofelemer is excreted in the human milk and thus may have unknown adverse effects on the nursing infants).
  • HIV positive individuals.
  • Persons within ability to provide consent and understand the study
  • Persons with history of alcohol abuse or binge drinking.
  • Persons with history of surgical bowel resection or bariatric surgery in the past 12 months.
  • Persons who have undergone cholecystectomy (open or laparoscopic) in the past 3 months.
  • Persons receiving antibiotics currently or have received antimicrobials in the past 4 weeks.
  • Persons with end-organ failures including end-stage renal disease, end-stage liver disease, or severe heart failure.
  • Persons with metastatic hematologic and oncologic malignancies.
  • Persons receiving chemo-radiation or immune-modulators for oncologic or rheumatologic conditions.
  • Persons with any other known organic gastrointestinal or non-gastrointestinal disease process in which diarrhea is a recognized clinical feature.
  • Gluten free diet for previous 3 months and refusal to ingest gluten.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Crofelemer and Diagnostic tests for cause of chronic diarrhea
125 mg tablets taken by mouth twice daily for 28 days
Drug: Crofelemer
125 mg tablets taken by mouth twice daily for 28 days
Diagnostic test: Diagnostic tests for cause of chronic diarrhea
Diagnostic tests include: Esophagogastroduodenoscopy, Colonoscopy, biopsies of the upper gastrointestinal tract (duodenum) and lower gastrointestinal tract (colon), genetic testing for Congenital sucrase-isomaltase deficiency (CSID),Prometheus IBcause Chronic Diarrhea panel, Thyroid Panel, Stool osmolality, Stool Ova and Parasites, Stool Culture, Stool Qualitative Stool Fat, Stool Reducing Substances, Laxative Screening, Lactulose Hydrogen Breath Test, Gastrin Level, Calcitonin Level, Vasoactive Intestinal Polypeptide(VIP) level.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time Frame: Week 1
Week 1
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time Frame: Week 2
Week 2
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time Frame: Week 3
Week 3
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time Frame: Week 4
Week 4

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of Participants With an Improvement in Stool Consistency by More Than 2 Levels as Measured by the Bristol Stool Form Scale
Time Frame: week 4
The Bristol stool form scale is a validated 1-7 scale that correlates to stool form. Type 1 is pebble like stool, type 2 lumpy and hard, type 3 like a sausage with cracks on the surface type 4 like a sausage but smooth and soft, type 5 soft blobs with clear cut edges, type 6 fluffy pieces with ragged edges, mushy stool, type 7watery, no solid pieces Types 5-7 are consistent with diarrhea and for this study a movement to lower types is considered an improvement
week 4
Physical, Psychological, and Social Functioning as Measured by the Health-related Quality of Life (HRQOL) Questionnaire
Time Frame: Baseline,week 4 of treatment
Health-related quality of life questionnaire assesses psychological, and social functioning. The total score ranges from 0 to 100 with higher scores indicate better quality of life.
Baseline,week 4 of treatment
Number of Participants With Any Abnormal Diagnostic Test Results Leading to the Identification of the Cause of Chronic Diarrhea
Time Frame: Baseline
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The University of Texas Health Science Center, Houston

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Napo Pharmaceuticals, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Brooks Cash, MD, The University of Texas Health Sciences Center at Houston

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 30, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 29, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 29, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 2, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HSC-MS-18-0990

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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