Final answer:
The correct nursing action for caring for a newly placed gastrostomy tube is to check the tube placement before each feeding or medication administration. Other actions include changing the dressing daily and avoiding the use of hydrogen peroxide to clean the insertion site.
Step-by-step explanation:
The correct nursing action for caring for a newly placed gastrostomy tube of a postoperative patient is to check the tube placement before each feeding or medication administration. This is important to ensure that the tube is properly positioned and to prevent complications. Administering medications through the tube without flushing first can lead to medication residue build-up and clogging of the tube. Changing the dressing around the tube daily helps to maintain cleanliness and prevent infection. Using hydrogen peroxide to clean the insertion site is not recommended as it can damage the delicate tissues.