I do an enema when I know I have a mess there and its being a little slow to come out. Or, of course, if Im preparing for sex.
Ive found that cold water makes the cramps worse whereas if the water is lukewarm or body temp then theres less cramps if any.
My enema bulb often lets a little bit of air into my body while Im doing the enema which results in some amazing squishy noises when I release.