Definition - What does Enema mean?
An enema is the practice of injecting liquid into the rectum to cause a bowel movement. This process is also used as a means to clean the rectum in preparation for anal play. When using an enema in this manner, it is important to understand the difference between that and the enema one would perform to relieve constipation. When cleaning the rectum, you will be using pure water. The water is injected into the rectum, held for several minutes, and released into a toilet bowl. Sometimes the enema will be repeated until the water exiting the body comes out completely clear.
Kinkly explains Enema
An enema is by no means a "necessary" step when engaging in anal play. Some people prefer the feeling of cleanliness they get from performing one, but many people find that a regular shower works fine as well. An enema is simply an option available to those who wish to use it.