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

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.