Final answer:
The amount of fluid to be used in an adult enema is typically around 500 mL.
Step-by-step explanation:
The amount of fluid to be used in an adult enema can vary depending on the specific situation and individual needs. The large intestine of an adult human has a volume between 6 and 7 liters, but the actual amount of fluid used in an enema is typically much less. A common recommendation is to use around 500 mL (or 0.5 liters) of fluid for an adult enema.