The fact is that unprotected anal sex puts individuals at risk of numerous anal STDs, including:
Risk for these diseases is, in fact, often substantially greater for unprotected anal sex than it is for unprotected vaginal sex. This is in part because the tissues of the rectum are more delicate and susceptible to tearing, which can increase the risk of infection for both partners. The rectum also lacks some of the natural protective features of the vagina, such as lubrication.
Because of the high STD risk associated with unprotected anal sex, it is extremely important for anyone who has anal sex to always have safe anal sex, and to talk to their doctor about testing for anal STDs. Although safe anal sex can not entirely eliminate the risks of contracting an anal STD, it can vastly reduce them. Safe anal sex means using a latex, polyurethane, or polyisoprene condom, along with plenty of condom-compatible lubrication, every time you have anal sex. It is also important to use gloves to cover the fingers and hands when manually penetrating a partner's rectum and to use dental dams for rimming.