Ginger Ale can help with the stomach flu but be aware that drinking too much Ginger Ale can worsen diarrhea which can cause you to lose more electrolytes when you're experiencing diarrhea.
The best thing to drink when you have the stomach flu is water and Pedialyte.
Pedialyte is marketed towards children and toddlers but adults can drink Pedialyte too and it's great to drink when you have the regular flu and stomach flu to help replace the lost electrolytes in your body.