Can you get chronic non-bacterial prostatitis from receiving anal sex? Oral-to-anal contact, whether from kissing or from oral contact with fingers that have been touching the anus can spread bacteria and cause infection. Practicing safer sex can prevent STDs in men and women. Lines and paragraphs break automatically. Anal sex does not cause hemorrhoids but may exacerbate them. Leave the poop on the back door. This is called a fistula and it is a significant medical issue because it allows feces to pass outside of the bowel, and requires major surgery to repair.