Must be at least 18 years old, with individuals 65 years of age or older encouraged to participate.

Must have a history of chronic diarrhea lasting at least 4 weeks.

Must not have recently used antibiotics or other conflicting medications.

Requires meeting with a study physician to determine full eligibility.

The study physician will assess if the study is right for you.

Additional medical and lifestyle factors may be evaluated during the screening process.