If you've experienced dehydration, stick to foods that are easily digested for the next 24 hours, because stomach cramps are a symptom of dehydration and can recur. Try soda crackers, rice, bananas, potatoes and flavored gelatins. Gelatins are especially good since they are primarily made of water.
You can also start and end your day with 16 ounces of water. It's a great way to prevent mild dehydration.