Thank you everyone for your replies! I have ordered some coconut water, and I did an internet search for 'electrolyte replacement drink recipes'! I found another recipe, which we made, and it tastes very, very good. I modified it just a bit from what was recommended.
In case anyone is interested it is:
1 qt. water
1/2 tsp. salt (I used Celtic Sea Salt)
2 tbsp. Honey
2 bananas
I blended this for about a minute and poured into a jar. We tasted it right away, and even without it being chilled it was delicious!
Thanks again! -
Camille
PS - He is already beginning to feel much better after eating some bananas, drinking the banana water, and going for a couple of walks today!