Anal sex is a regular activity in my house for 12 years. I have never needed to see a doctor about it. I have
never had bleeding, pain, burning, tearing, aching, or anything and neither has my guy. I have never lost control of my bowels or any other horror story that people imagine about anal sex.
The only physical differences I notice are that it feels really comfortable afterwards, and I usually go to the toilet very regularly but sometimes having anal sex will delay things for a few hours or until the next morning.
We accomplish this by taking it slow, using lube, changing things right away if either of us feels any discomfort, and picking the right time. Not every time is the right time, either because a trip to the toilet is in the near future, or because it just doesn't feel right when you start. If it feels wrong we'll usually just grab a shower and try something else, but we don't keep banging away at something that feels uncomfortable. That gives us as much anal as we want, and I'm not kidding we only do it for the pleasure, which is possible to experience several times a week.
You can find lots of people who say you have to just endure it until you get used to it, but I have a 12 year track record now of not needing a doctor and having good sex and I say that I would never do that.
In my life, I have heard one story of a guy needing to get stitches because his (new, one-night-stand) partner was rough and significantly bigger than average. I don't know if it was true, it was a gossipy friend-of-a-friend-of-a-friend thing. I have heard an identical story about a woman from a friend at work about a bigger than average guy taking him vaginally. However my guy is really big around, and it hasn't been a problem because we decided not to do anything stupid, hasty or rough that would make it a problem.
All I know is after 12 years, everything works very very well. My doctor has examined me thoroughly, inside and out, as part of a general medical, and he had no problems with anything back there. My guy even had a colonoscopy for something totally unrelated to anal sex, and they found no problems back there either on the way in or deeper inside than any penis could ever reach.
With a patient partner, my experience is that the risk is low, and with a bit of thinking you can keep it low.
The biggest risks I know of are:
a) HIV transmission - well known risk, important not to sleep with strangers who may not know their status
b) HPV leading to an increased risk of anal cancer - this is something they are only figuring out more recently. HPV has many varieties, that can appear as anal warts, or some varieties can infect someone without obvious symptoms. It can increase the risk of anal cancer years later. There is also a vaccine for it called Gardasil or Silgard depending on the country. There is also screening for HPV at sexual health clinics. To my knowledge, testing is not universal, and there is still research being done on transmission, etc. Again though, everybody needs to get checked by a doctor back there starting at middle age so they can get any problem spots before they have a chance to even turn cancerous. That isn't an anal-sex thing, that is a mid-life thing.
As my guy and I are monogamous and don't have either of those pre-existing concerns, it is good for our health.I can't imagine a hook-up being a good situation for anal sex for many reasons, but for me and my guy, after 12 years, we've figured out what we're doing, and we have more anal now that we have figured it out. Slow and easy, and it all feels good.
Keep in mind that high cholesterol and blood pressure are still much greater threats to your health. And anal sex does a lot of good for my blood pressure because it is soooo relaxing!
) ) then you would find me the next day at my doctor's office saying to my 55 year old straight male doctor "Yeah, I was getting fucked last night and we moved the wrong way and I need you to check back there."