you would fart out a bunch of vapor made of oils, which would lubricate your ass and make you have explosive diarrhea all over everything
I'd keep doing it untill my ass was dirty with resin, scrape it and call it ass hash and sell it 200 dollars a gram.
You'd probably ruin your body forever, resulting in pooping out of your mouth, and forcing food through your ass for the rest of you life =/
There's only one way to discover this, and it rhymes with "lie mitt trout". It'll make a great story to tell in twenty years: "Hey, did I ever tell you about the time I forced cannabis vapor into my rectum?" "No, that sounds disgusting." "Yeah, disgustingly awesome, biatch!"