It ain't so bad. Just remember that when you drink that saline enema, mix it with some Sprite or something (clear fluids help the doc see inside your a..).
Oh yeah, after you drink it (it tastes absolutely awful, even in Sprite), stay very close to a bathroom, just like the label states.
You won't believe how much fluid can come out of your body. It will amaze you!
I have ulcerative colitis, these things are routine now.