How often can one have anal sex with out negative consequences?

I'm a girl but am posting here because posting in /r/sex didn't get great results.

My SO really really loves anal. I started doing anal frequently around a year ago, however, because I didn't really enjoy the pain and because we live an hour away from one another we didn't do anal too frequently. Maybe once a month.

Now I really like it. Maybe more than vaginal sex sometimes.

I'm worried about the health consequences. We use coconut oil as lube (though sometimes we settle for ALOT of saliva) and he thrusts rather hard. This goes on for maybe 20 minutes? Which means every two wks or so I have 1-1.5 hrs of active dick thrusting into my ass.

I've noticed I've gotten obviously easier to access. It use to be a lot of work just to get him in but now it's much easier. The puckered skin around my asshole is also softer? Does this mean something?

I'm worried about things like incontinence and the like. Do any of you have any advice or insight?