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

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: Completed
• Conditions: Chronic Diarrhea of Unknown Origin
• Intervention / Treatment: Drug: Crofelemer; Diagnostic test: Diagnostic tests for cause of chronic diarrhea

• Study Type: Interventional
• Enrollment (Actual): 93
• Phase: Phase 4

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

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

Outcome Measure	Time Frame
Number of Participants With a 50 Percent Decrease in Mean Stool Count	Week 1
Number of Participants With a 50 Percent Decrease in Mean Stool Count	Week 2
Number of Participants With a 50 Percent Decrease in Mean Stool Count	Week 3
Number of Participants With a 50 Percent Decrease in Mean Stool Count	Week 4

Secondary Outcome Measures

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	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	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		Baseline

Collaborators and Investigators

• Sponsor: The University of Texas Health Science Center, Houston
• Collaborators: Napo Pharmaceuticals, Inc.
• Investigators: Principal Investigator: Brooks Cash, MD, The University of Texas Health Sciences Center at Houston

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2019
• Primary Completion (Actual): January 30, 2025
• Study Completion (Actual): January 30, 2025

Study Registration Dates

• First Submitted: March 29, 2019
• First Submitted That Met QC Criteria: March 29, 2019
• First Posted (Actual): April 2, 2019

Study Record Updates

• Last Update Posted (Actual): February 12, 2026
• Last Update Submitted That Met QC Criteria: January 26, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: treatment; diarrhea; diagnosis; crofelemer
• Additional Relevant MeSH Terms: Pathologic Processes; Signs and Symptoms, Digestive; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Disease; Diarrhea; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Tests, Routine; crofelemer
• Other Study ID 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