It has been more than five years since I first responded to this thread and a number of things have changed for me.
First, it had been a very long time since I had shared-enema experiences with anyone (giving, receiving, or sharing). Since I had responded in 2018, I have had a number of in-person experiences where it is not a solo experience. The thing that is still true for me, that was true decades ago, is that like-minded people like ALL aspects of the enema experience including the expulsion. It's the natural consequence of what we do. We don't hide behind closed doors when expelling and may even be engaged in blumpkin/clumpkin experiences during the expulsion (I didn't know there were slang words for some of the things I did many years ago).
With the exception of the high concentration glycerin enemas that I've experimented with (that close off my rectum and makes it hypersensitive to anything), I still like the sensation of the liquid and the clumps moving down my descending colon, through my Sigmoid, and out my rectum. It's the sensation that signals the flushing out / cleaning out of my colon. After the sensation of filling and then the fullness that cums with it, it's the release of the of all the liquid, the softened matter, and liquified matter that was such a challenge to hold that feels so good (even if messy and smelly). It's letting those muscles that release and relief after they have been under tension to hold the enema inside you.
I still have different sensations filling, holding, and expelling. I was reminded of that again today when I took a 3.5 liter coffee enema (I hadn't done one in a while). All are phases are/were enjoyable over the filling, the big belly retention, and the release phase. They were made even better by being able to share them with a good friend who appreciates all aspects of the enema experience.