These are clips re: your question:
Is Gatorade safe for infants and toddlers?
While Gatorade should never be used as a substitute for milk, infants and toddlers can safely drink Gatorade once they are weaned off breast milk or formula and begin consuming food, fruit juices and other beverages. It is best to consult with your pediatrician prior to introducing new foods into your infant�s diet.
Why do some pediatricians recommend Gatorade?
Pediatricians frequently recommend Gatorade to keep children adequately hydrated. Sick kids can dehydrate quickly by losing fluid as a result of fever (sweating) and diarrhea. Pediatricians know that Gatorade helps put back fluids and electrolytes fast.
One thing to keep in mind is that Gatorade is a sports drink and is not specifically formulated as an oral rehydration solution for persistent, severe diarrhea. Please consult with your pediatrician if persistent, severe diarrhea develops.
I'd keep in mind this comes from the Gatorade web site, but others seem to correspond with their advice. It's probably better than sugar laden soft drinks...