My ideal role play fantasy enema would take place in the context of an ageplay scenario. Imaginary partner would play the role of my babysitter, aunt/uncle, what have you. Though not strictly a punishment per se, the enema would be prescribed as a treatment for sullen, fussy behavior.
I would engage in some sort of misdeed-back talking, general brattiness, etc. After hoisting me over their lap for a quick spanking, my partner suddenly decides to give me a manual rectal exam, no warning, no lube. I'd howl from the dry finger's brusque insertion, fussing while they hold me in place with their free hand on my lower back. They would then declare that my behavior might be the result of constipation, and resolve to correct that.
I am hauled to a nearby corner, and am left sniffling with my nose pushed against the wall. As I continue to sob at the indignity of it all, I can hear water running in the bathroom. When my partner finally emerges, they take my hand and wrench it behind my back. They begin anoher hand spanking, right there, and continue it as they march me to my bedroom. It's not the tastefully appointed room we share. Instead, it's a small, childishly decorated space, with a twin bed for treatments, play, and sleep.
Play is not what my partner has in mind. A thick, clear plastic fitted sheet covers the bedding, and the restraints which are strapped to the mattress are out of their hiding place, soft cuffs standing in sharp relief against the slick plastic. Their position precludes mine; ankle cuffs halfway up the bed indicate that I will be bent over, knee to chest.
The cuffs didn't lie. I soon find myself in them, bottom high in the air. The bulging enema bag hangs from a hook, suds clinging to its surface. I squeal that I don't need an enema, that I'll be good. My pacifier gag is summarily shoved into my open mouth and buckled behind my head. Another hand spanking follows, with my partner emphasizing how they know what I need far better than I do. My behavior makes that point obvious.
I scan the room as I choke back muffled sobs, dimly aware of my partner lubricating the inflatable nozzle. A feeling of dread settles in the pit of my stomach when I notice what objects are out of their typical hiding places for use: a paddle, a stack of thick disposable diapers, and, worst of all, an antique, stylized potty. It's going to be a long night.