I've read the post about "Enemas & Submission" as well as the others....
For me (sub female) it's definitely about submission, and I can't think of sharing anything more intimate, sensual, entrusting and submissive than receiving an enema while being restrained.
Yes, restrained. Trusting your partner/Dom/Dr to position you, to watch over you, determine how you'll receive, to tell you when & how it's time to release. Perhaps while in restraints he offers other stimulation, and you have no choice but accept the pleasure you are being offered.
I don't see anyone talk much about combining the pleasures of enema/med-play with BDSM, particularly restraints.
I'm listening, do tell....
-A