Someone else mentioned celebs talking openly about colonic irrigation. You even have Paris Hilton doing it. Not that I admire her by any means, but people like her and others are bringing the topic of colonic irrigation into the media and into pop culture. I believe colonic irrigation is on the wispy fringe of becoming a (not the) new "In Thing", but I wouldn't say the same of self-administered or partner-administered enemas, especially in a sexual context.
Then there's the topic of colon health and detox in general. It's talked about on network television, cable TV, magazines and other media outlets. Perhaps this ties in somewhat with the resurgence of colonic irrigation.
Another item that may bring enemas for health back into more of a mainsream position is our growing concern about taking pharmaceutical drugs. Many people today think twice before taking medication, whether OTC or prescribed. However, I don't see enemas soon becoming as openly accepted as they were back in the first half of the 20th century.
In sum, I think the enema will linger on the fringe at best, but perhaps it won't be considered such a horrible thing as it was in the latter half of the 20th century.
And, you know, when the enema was popular it also brought out the worst in some people. Parents would force their kids and even use enemas as punishment. I'd call that child abuse. Those halcyon days perhaps weren't so grand.
Arianna