I've made up a lot of words and "autoanalism" isn't one of them. Nor did I invent inserting one's own penis into one's own asshole. That was what happens when there's nothing to watch on TV.
Rather I saw the word on a vintage magazine from a time in which medical case studies were written for a purely educational higher purpose. There was certainly no prurient intent. Nope, it's all just basic humdrum information about self-fucking.
And self-internal-cumshots and self-handsfree-prostate-massage and self-haircut. Because if you can fuck yourself surely you can trim your own sideburns.
Try not to think about certain terrifying scenes from horror movies involving snakes or tentacle aliens even though these shots in their unpredictability are a bit creepy and confusing. At least my mind will think that can't possibly be a penis right there as how does he manage that miraculous feat? So it must be a tentacle alien.
Or a dildo if you naturally theorize something more innocuous.
I would absolutely insist on seeing the guy from fully dressed to stripped down to getting hard to insertion. Monitoring exactly what's happening during this complex act should be closely observed and documented. For medical science.