Final answer:
The client understands the teaching of colostomy irrigations when they demonstrate the correct technique for performing the procedure.
Step-by-step explanation:
The action that indicates that the client understood the teaching of colostomy irrigations is when they demonstrate the correct technique for performing the procedure. This includes maintaining sterility by properly washing hands, using clean equipment, and following the step-by-step process for irrigation. For example, the client should correctly insert the irrigation tube into the stoma, instill the appropriate amount of fluid, and allow the liquid to flow into the colon before evacuating the contents into a collection bag.