Bob,I am a heterosexual male in my mid 20's and now engaged. This increases the likelihood of passing infections, viruses, or bacteria between partners. Anal sex can just be a fun way to play. Sex toys , like vibrators , dildos , and butt plugs , are used too. Perianal tumours can also discharge when they fungate, or otherwise become cystic or necrotic. A toy might be a good option, too, as you grow more comfortable with the sensation. People who have anal sex have a higher risk of sharing STIs, but using a condom or dental dam reduces that risk.
Want to add to the discussion? Otherwise, bleeding could be an indication of internal or external hemorroids. Prescription estrogen can work well to treat atrophic vaginitis. Hemmoroids are more common to occur to women.
And most doctors won't give advice online, either, because it's unprofessional to offer a diagnosis without a proper examination and doing relevant tests. Instead of saying, "either deal with the blood or don't have anal sex," a doctor could give advice for having safe anal sex. It is the cracking inside the anus. Are you saying the OP's partner wasn't wrong in the forcefulness he exhibited during anal sex? Jumper HairyD comments to justneed2know was she should have told her partner she was want to stop.