Final answer:
The patient should retain the cleansing enema solution for a specific amount of time depending on its purpose, such as softening stool or delivering medication.
Step-by-step explanation:
The patient should retain the cleansing enema solution for a certain amount of time to allow it to work effectively. The retention time for the enema solution can vary depending on the specific purpose of the enema. For example, a cleansing enema is typically retained for about 5-10 minutes to allow the solution to soften and loosen stool before being expelled. On the other hand, a retention enema, which is intended to deliver medication, may need to be retained for a longer period, such as 20-30 minutes, to allow for optimal absorption of the medication by the body.