Having an intoxicant enema, the main purpose of which is to bypass the vomiting reflex, though it also causes the active ingredients to be absorbed faster, for more fun and greater tissue damage. Apparently Mayan priests used to do this with mixtures of alcohol and powerful tropical hallucinogens, and the ones who survived often had strange insights, now sadly lost to us.
Could we possibly come up with something to do apart from butt chugging this weekend? My 'rhoids are acting up.
Although the original Freudian idea of the evolution of the character through various stages like the "anal stage", at each of which it was possible to get stuck, has not really stood the test of time, many outside the psychological community feel that it's still worth having a term for those backed-up individuals one occasionally encounters who have an abiding need to stop fussing about something or other and relax, unclench, and *blow it out their ass*. For this, "anally retentive" (or simply "anal") will serve as well as anything.
He's so anally retentive only dogs can hear him fart.