Trying to remember back to a point some 70 years ago, my first enema was from a bag. That was all my mother, grandmother, and great aunt ever had, so that is what was used on me. I was constipated for a couple of days when my mother figured out that was what was wrong with me. That was when I experienced my very first enema at the age of 4. I hated it and could not wait for the experience to be over with. I kicked and screamed the whole time.
Move forward about another 6 years and perhaps maybe a100+ enemas later, and all of a sudden, my enemas started to feel good. That was when I got addicted to enemas. Of course, I never let on that I liked them and fought the whole time. I never let on that I had grown to like my enemas. In fact, I used to fake having constipation in order to have my mother administer a nice warm slightly soapy enema as the cure.
Then around age 11 or 12, I gave myself my first solo enema and have been doing it ever since. I have never liked getting a bulb enema and always prefer and use "the bag". Early on, my volume was less than a quart, but as I grew up the volume got larger and now my normal volume is about 3 quarts taken while sitting or sometimes standing.
My enemas tend to contribute to having an erection and I do masturbate. Back when I was about 15 or so, I was giving myself an enema and had a full throbbing erection which I was stroking when all of a sudden, I ejaculated. That one experience locked in enemas as a permanent part of my life.