This study is comparing rectal and oral Tenofavir-based prep. The rectal study product is a rectal douche, or enema, that contains the anti-HIV drug tenofovir (TFV). The other study product is taken by mouth and is a combination of two drugs, called emtricitabine (FTC or F) and tenofovir disoproxil fumarate (TDF).
Tenofovir (TFV) rectal douche is considered investigational because it is not approved by the U.S. Food and Drug Administration (FDA). Emtricitabine/Tenofovir Disoproxil Fumarate (FTC/TDF) is FDA-approved and used according to FDA labeling.