I have to agree with hberry4458. I like standing and I think I have more control over the flow and filling. I feel I get filled up better standing and I get a much higher enema standing. I find the nozzle does stay in better standing and I can also squeeze my buttocks and hold it better. I do bend over at times, then I usually arch my back and allow more water to flow higher.
I have tried lying down, as others have said, getting up usually causes some problem. Either leakage, the nozzle comes out and then there is a mess to clean up, then I have to get to the shower to release, since I have a choice, toilet or shower and I am usually closer to the shower than the toilet.
Also if there are any gas or air bubbles they move up easier and I am able to burp them out of my system.
I also like the feel of the water moving up and filling my inside. When the warm water crosses over and into the cecum and fills it up, it is a real turn on and then I feel really full. If I wait a few minutes, now and then the water moves higher, but only on occasion.
With my new larger nozzle, I don't to squeeze as much as in the past. The smaller nozzle needed to be held in much more.