What are the health risks of ejaculation in rectum?

STD: Unprotected intercourse of any kind, whether or not ejaculation occurs, can result in transmission of HIV and other sexually transmitted infections. Consider using condoms.

Rectal sex: The rectum is not really made for vigorous and repeated insertion of external things. Such activity may damage its lining or cause more extensive injury. Unprotected rectal sex (without a condom) also allows exposure to std's, including hiv. If the person ejaculating is hiv+, there is more risk of the latter.

Minimize the Risks: From us centers for disease control: "40% of men & 35% of women have had anal sex w/ an opposite-sex partner. About 6.5% of men 25-44 yrs...Have had oral or anal sex with w/ another man." (source http://1.Usa.Gov/18gmycm) using condoms & water-based lubricants is a must b/c anus/rectum lack natural lubrication which can lead 2 tears & exposure 2 blood which means it's easy 2 transmit stds, esp hiv.