An enema is an instrument to put water into your rectum to clean it. It’s also called an anal douche.
In the medical world this is sometimes done before surgery to cleanse the colon.
It also used by people who enjoy anal sex. To make sure feces don’t spoil the fun they clean their rectum before having sex. Others do it because they love the stimulation provided by an enema.
Most people use a bottle or bag with a long nozzle they can insert in their anus. But it’s also possible to fix a hose between the water supply and the shower head.
You fill the instrument with water, put some water-based lubricant around your anus, insert the nozzle one or two inches into the anus and introduce the water. This has to be done slowly. The water stays in a while to soak off waste products from the walls of the colon. After a while (2 to 20 minutes) you feel the urge to release. You go to the bathroom where you let the water run out.

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