Final answer:
After instilling 100 mL of enema fluid in a return-flow enema, the nurse should let the fluid flow back out, repeating the process as necessary under healthcare provider instructions for expelling flatus and stimulating peristalsis.
Step-by-step explanation:
When a nurse is administering a return-flow enema to a patient, after instilling 100 mL of enema fluid, the nurse should then allow the fluid to flow back out.
This process may be repeated several times according to the instructions of the healthcare provider or until the expelled fluid is clear. The return-flow enema is used to expel flatus and stimulate peristalsis without causing significant distention of the bowel.
It is important for the nurse to monitor the patient closely for any signs of discomfort or complications throughout the procedure.