We bought sticky out handles, which I regret, not because they have got stuck up my arse (trust me, this is not the sort of DIY activity I involve myself in), but the number of times I've painfully whacked them with the back of my hands (I even have a scar from one occasion). This might, in part, be down to the fact that I walk like a monkey though. Or so I'm told.
Should have bought round doorknobs, which was my preference in the first place.
As a break from tales of curious anal insertions, the best study I saw was about a bloke who somehow managed to insert his scrotum and testicles through a large and very substantial metal nut. However he'd got them in, no amount of diligence was going to get them out again, so after a couple of days of pain and strangulated testes, he finally had to visit A&E, presumably walking big leggy style, but I mean, it was the sort of nut that looked like it might hold tractor wheels on. No amount of lubricated medical manhandling could remove the offending item either, so in the end it came down to a careful application of power tools, and they had to grind it off. I'm told he made a full recovery. Men, in general, should not be allowed access to their own parts.