"How much is too much anal sex?"
Is it dangerous to have regular anal sex? I’m with the same partner so I’m not concerned about STDs just physical damage.
Here’s the good news: having anal regularly won’t make you ‘loose’ or lead to you being unable to control your bowel movements. (It could, however make you more inclined to break wind for a few hours afterward because the sphincter and rectum are stretched during anal and air can be introduced, but that’s another story!). But - and its an important but - this is if you are having anal sex safely and sensibly.
The lining of the anus is delicate: you need to be using a good quality, heavy duty anal lube and reapply regularly. You need to be gentle. You need to stop if it really starts to hurt. If it’s male/female anal, you need to wash his penis or any toys or fingers used during anal play before going anywhere near her vagina to avoid transferring bacteria. If you do develop a tear in the lining of the anus, don’t have anal sex until it’s fully healed. If it doesn’t heal and gets worse, it may have developed into a ‘fissure’: a larger tear or crack. If this happens, you must see a doctor. It won’t heal on its own. Anal sex may also make hemorrhoids worse if you have them.
Other than that, you’re fine but bear in mind that - unlike the vagina - the rectum is built to have things coming out of it, rather than inserted into it. It copes pretty well, under the circumstances, but It’s not designed for that purpose and for that reason, personally, I wouldn’t be at it every single day of the year.