To assess the efficacy of Saccharomyces boulardii (a nonpathogenic yeast) in producing a significant reduction in diarrheal symptoms in HIV-infected patients with chronic diarrhea.

Inclusion Criteria

Concurrent Medication:

Allowed:

• Antiviral medication for HIV infection.

Patients must have:

• Documented HIV infection.
• Chronic diarrhea (for at least 1 month) that is either a manifestation or complication of documented HIV infection.
• Had a stool culture (Salmonella, Shigella, Campylobacter, and Clostridium difficile) and stool analysis for ova and parasite (O/P X 3) within the past 2 months.
• Failed antimicrobial treatment for diarrhea OR received no prior antimicrobials for stool pathogens because stool cultures were negative.

Patients who are on antiviral medications for HIV infection must have received such medication for at least 2 weeks and must remain on stable dose for weeks 1 and 2 of study.

Prior Medication:

Allowed:

• Prior antiviral medication for HIV infection (if on such medication, must have received it for at least 2 weeks).
• Standard antimicrobial therapy for a documented positive gastrointestinal pathogen.

Exclusion Criteria

Concurrent Medication:

Excluded:

• Gastrointestinal medications that cause diarrhea (e.g., magnesium-containing antacids, lactulose).
• Maintenance antifungal medication for life-threatening fungal infections (other than fluconazole <= 100 mg/day).