In the United States, it is an uncommonly reported disease with fewer than cases in Residual confounding could influence these findings, given the clustering of unprotected anal intercourse with other measured and unmeasured risk behaviors. It is important to use a condom when having anal sex std from anal sex prevent pregnancy. Doctors call this std from anal sex fistula. Murrill, T. Homelessness was defined as living on the street, in a shelter, or in a single-room occupancy apartment in the past year. It includes discussions of gonorrhea, campylobacter, chlamydia, shigella, chancroid, granuloma inguinale, and syphilis.