PRIMARY: To compare the frequency of and time to relapse of Cytomegalovirus (CMV) gastrointestinal disease following foscarnet induction therapy only versus induction plus maintenance therapy.

SECONDARY: To determine frequency of and time to recurrence of gastrointestinal symptoms, response rate of pathological lesions, and incidence of nongastrointestinal CMV disease in this patient population.

Patients receive intravenous foscarnet either as induction only for 4 weeks or as induction for 4 weeks followed by maintenance for 22 weeks. All patients are followed for 26 weeks or until relapse.

Inclusion Criteria

Patients must have:

• AIDS.
• CMV GI disease.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Non-GI CMV disease.
• Ulcerative colitis, inflammatory bowel disease, or other condition that may interfere with study results.
• Other GI pathogens.

Concurrent Medication:

Excluded:

• Drugs that may interact with foscarnet.
• Systemic acyclovir, ganciclovir, or acyclovir prodrug.
• Drugs known to affect renal function.

Prior Medication:

Excluded:

• Prior foscarnet in extremis.
• Investigational agents other than 3TC or d4T within 7 days prior to study entry.