My 10 month old baby has stomach flu how long or days should the diahrrea last and all the sympthoms? she's in playful but don't eat 2 too much formula

Stomach "flu": (viral) usually last 24-48 hours. Keep baby hydrated with sips of pedialyte/formula/ watered down juice. Since she's playful, symptoms should rapidly subside. Bacterial gastroenteritis' symptoms may be more severe & last longer so that medical intervention may be needed to prevent dehydration. Braty diet (banana, rice, applesauce, toast, yogurt) may help, too.