I do stand up shower enemas all the time, there's no equipment to have and to set up and I like the flow, and I just squeeze my asshole tighter to control the flow, if I want, I can blow the water easily out of my asshole to regulate the pressure/cramps. Plus, I like releasing it all in the shower, just the way I am, I find it hot to do.
And I can easily regulate the flow, some days I like fast enemas, others slow, but I always keep the valve pressure low, and give the temperature lots of time to stabilize, and the tap water here is very safe. Yep, I'll be doing this tonight, sometimes if the hose is long enough I do shower squats or dogie with mirrors for the whole show, in and out. It's a blast, so to say! I shoot a really good stream! Warning, enema release in process! LOL! And sometimes with a long hose I stick it up my ass just beyond the second sphincter, never further for me, I don't have a colon tube.
I also play with my tits as I do this, my dick gets so hard it's unbelievable. It's so hard it tingles, seriously.