Final answer:
Notify the surgeon about the red and edematous stoma in the newborn with a colostomy.
Step-by-step explanation:
The appropriate nursing intervention for a red and edematous stoma in a newborn with a colostomy is to notify the surgeon about the findings. The redness and swelling may indicate an infection or other complications that require medical attention. It is important to involve the surgeon and follow their guidance in such cases to ensure the appropriate care for the newborn.