Inclusion Criteria

Concurrent Medication:

Allowed:

• Antidiarrheal compounds (if dose remains stable).
• Zidovudine (AZT), dideoxyinosine (ddI), dideoxycytidine (ddC), or alternative HIV therapy (provided dose was stable for at least 4 weeks prior to study entry).

Patients must have:

• AIDS.
• Cryptosporidium parvum enteritis.
• Chronic diarrhea.
• Life expectancy of at least 4 weeks.
• Ability to tolerate food by mouth.
• Ability to take the histamine H2-receptor antagonist famotidine (Pepcid).

Prior Medication:

Allowed:

• Antidiarrheal compounds (provided dose has remained stable in the 7 days prior to study entry).
• Zidovudine (AZT), dideoxyinosine (ddI), dideoxycytidine (ddC), or alternative HIV therapy (provided dose has remained stable for at least 4 weeks prior to study entry).

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Concurrent unresolved clinical infections with enteric pathogens other than C. parvum (e.g., rotavirus, Salmonella, Shigella, Campylobacter, Giardia, C. difficile toxin, Yersinia, amebiasis, MAI, CMV, Microsporida) as determined by history or routine microbiology screening.
• Other acute infections or concurrent immediately life-threatening medical crisis other than cryptosporidiosis.
• Grossly bloody diarrhea.
• Known allergy to milk or milk products (other than lactose intolerance).

Prior Medication:

Excluded:

• Other experimental therapy (e.g., macrolide antibiotics, paromomycin) within 30 days prior to study entry.