Final answer:
The nurse would advise increased fluid intake for a 3-year-old with mild diarrhea. Easy-to-digest foods like the BRAT diet can help firm up the stools. The nurse would also recommend avoiding dairy products.
Step-by-step explanation:
The nurse would advise increased fluid intake for a 3-year-old with mild diarrhea. This is because diarrhea can lead to dehydration, and replenishing fluids is important for staying hydrated. The nurse may also suggest a diet that includes easy-to-digest foods such as bananas, rice, applesauce, and toast (BRAT diet), as these foods can help firm up the stools. Additionally, the nurse would advise avoiding certain foods that may worsen diarrhea, such as dairy products, as they can be harder to digest.