It has been, and likely always will be sexual.
I enjoy everything about enemas, preparation, insertion, filling, holding and expelling. Of course a full colon needing a flushing, and a good chunky expulsion are the best, I don't enjoy squirting clear water nearly as much.
I have never been a fan of capacity, 2 1/2 quarts is fine, 2 isn't quite enough, I can do 3 with stimulation by a partner, and probably made it to a gallon only once or twice.
I read stories of ridiculous amounts, which I don't believe and they turn me off, I like realism.
I have known two women who can get past the 6 quart mark, one a friend and the other that was one of Beth Tyler's earliest models.
Thanks to my first colon therapist I got into deeply inserted colon tubes, and even bought a sigmoidoscope on eBay to play with.
When watching enema videos, just like the way I enjoy my own, everything about the process is enjoyable, and a very chunky expulsion is far more exotic than clear water or milk.
I guess that about covers it!