Chronic Diarrhea of Unknown OriginPhase 4NCT03898856

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

A Phase 4 study testing Crofelemer and Diagnostic tests for cause of chronic diarrhea in people with Chronic Diarrhea of Unknown Origin, run by The University of Texas Health Science Center, Houston at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

Who is it for?: Ages 18 to 75 years
Conditions the study is for: Chronic Diarrhea of Unknown Origin
What is being tested?: Crofelemer and Diagnostic tests for cause of chronic diarrhea
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 93 participants
Where: 1 siteUnited States
Study dates: 1 Apr 2019to 30 Jan 2025
Phase: Phase 4
Are there results?: Yes, posted in the registrySummary in the doctors' view

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
No healthy volunteers
Adult, Older adult

Who may be able to join

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

Who cannot join

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

Show all 15Show fewer

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.

Trial locations and contacts

1 site in 1 country.

United States1 site

The University of Texas Health Science Center at Houston
Houston, Texas, 77030

Other trials in United States

About this study

Official title: 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.

Conditions: Chronic Diarrhea of Unknown Origin
Being tested: Crofelemer, Diagnostic tests for cause of chronic diarrhea
Keywords: diarrhea, diagnosis, crofelemer, treatment
Medical subject headings: Diarrhea, Disease

What participants receive

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

CrofelemerDrug
125 mg tablets taken by mouth twice daily for 28 days
Diagnostic tests for cause of chronic diarrheaDiagnostic test
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.

Study groups in NCT03898856
Study group	Role	What they receive
Crofelemer and Diagnostic tests for cause of chronic diarrhea	Experimental	125 mg tablets taken by mouth twice daily for 28 days Receives: Drug: Crofelemer; Diagnostic Test: Diagnostic tests for cause of chronic diarrhea

What is being measured

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

Number of Participants With a 50 Percent Decrease in Mean Stool Count
Measured: Week 1
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Measured: Week 2
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Measured: Week 3
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Measured: Week 4

Secondary outcomes (3)

Number of Participants With an Improvement in Stool Consistency by More Than 2 Levels as Measured by the Bristol Stool Form Scale
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
Measured: week 4
Physical, Psychological, and Social Functioning as Measured by the Health-related Quality of Life (HRQOL) Questionnaire
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.
Measured: Baseline,week 4 of treatment
Number of Participants With Any Abnormal Diagnostic Test Results Leading to the Identification of the Cause of Chronic Diarrhea
Measured: Baseline

Timeline

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

1 Apr 201930 Jan 2025

First posted2 Apr 2019
Study start1 Apr 2019
Primary completion30 Jan 2025
Study completion30 Jan 2025

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Chronic Diarrhea of Unknown OriginStudies of the same condition, open and under way.
More trials run by The University of Texas Health Science Center, HoustonThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

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 4
Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Enrolment: 93 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03898856
Sponsor's protocol ID: HSC-MS-18-0990
Status last verified: Jan 2026
First submitted: 29 Mar 2019
Last updated: 12 Feb 2026
Results posted: Yes, on ClinicalTrials.gov
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Study at a glance

From the registry record, last updated by the sponsor on 12 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Yield of Diagnostic Tests and Management of Crofelemer for Chronic Idiopathic Diarrhea In Non-HIV Patients: A Pilot Study
ClinicalTrials.gov ID: NCT03898856
Acronym / sponsor ID: HSC-MS-18-0990
Conditions: Chronic Diarrhea of Unknown Origin
Keywords: diarrhea, diagnosis, crofelemer, treatment
Phase: Phase 4
Study type: Interventional
Recruitment status: Completed
Enrolment: 93 participants (actual)
Lead sponsor: The University of Texas Health Science Center, HoustonUniversity, hospital or other
Collaborators: Napo Pharmaceuticals, Inc.
Study start: 1 Apr 2019 (actual)
Primary completion: 30 Jan 2025 (actual)
Study completion: 30 Jan 2025 (actual)
First posted: 2 Apr 2019 (actual)
Results: Posted 12 Feb 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1

Arm	Type	Receives
Crofelemer and Diagnostic tests for cause of chronic diarrhea	Experimental	Drug: Crofelemer, Diagnostic Test: Diagnostic tests for cause of chronic diarrhea125 mg tablets taken by mouth twice daily for 28 days

Who may qualify

Ages: 18 to 75 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (2 listed)

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

Key exclusion criteria (15 listed)

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.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Crofelemer125 mg tablets taken by mouth twice daily for 28 days	Drug	Crofelemer and Diagnostic tests for cause of chronic diarrhea
Diagnostic tests for cause of chronic diarrheaDiagnostic 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.	Diagnostic test	Crofelemer and Diagnostic tests for cause of chronic diarrhea

Primary outcome

Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time frame: Week 1
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time frame: Week 2
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time frame: Week 3
Number of Participants With a 50 Percent Decrease in Mean Stool Count
Time frame: Week 4

3 secondary outcomes

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
Physical, Psychological, and Social Functioning as Measured by the Health-related Quality of Life (HRQOL) Questionnaire
Time frame: 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

Results and safety

Results posted to the registry on 12 Feb 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Crofelemer and Diagnostic Tests for Cause of Chronic Diarrhea	93	23

Primary outcome: Number of Participants With a 50 Percent Decrease in Mean Stool Count

Time frame: Week 1. Count of participants. Unit: Participants

Measure	Crofelemer and Diagnostic Tests for Cause of Chronic Diarrhea n = 23
Value	17

Primary outcome: Number of Participants With a 50 Percent Decrease in Mean Stool Count

Time frame: Week 2. Count of participants. Unit: Participants

Measure	Crofelemer and Diagnostic Tests for Cause of Chronic Diarrhea n = 23
Value	16

Primary outcome: Number of Participants With a 50 Percent Decrease in Mean Stool Count

Time frame: Week 3. Count of participants. Unit: Participants

Measure	Crofelemer and Diagnostic Tests for Cause of Chronic Diarrhea n = 23
Value	18

Primary outcome: Number of Participants With a 50 Percent Decrease in Mean Stool Count

Time frame: Week 4. Count of participants. Unit: Participants

Measure	Crofelemer and Diagnostic Tests for Cause of Chronic Diarrhea n = 23
Value	17

3 secondary outcomes are reported in the full results.

Adverse events

Time frame: 4 Weeks. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Crofelemer and Diagnostic Tests for Cause of Chronic Diarrhea	0 of 93 (0%)	0 of 93 (0%)	0 of 93

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 12 Feb 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Brooks Cash, MD principal investigator

The University of Texas Health Sciences Center at Houston

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

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 2 inclusion and 15 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: finished, as of the sponsor's last update on 12 Feb 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.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 12 Feb 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With a 50 Percent Decrease in Mean Stool Count (time frame: Week 1). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03898856.

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 12 Feb 2026.