A tablespoon of yellow mustard. Eat it up yum. I have successfully used this to ease my upset stomachs for years.
I have a little boy(now four) who was premie. He had reflux and was constantly sick with stomach bugs. I tried everything and finally out of desperation tried half of a candycane in his bottle(Christmas time 'tis the season). He had been throwing up for days(hard scary kind of throwing up) and after two of those he ate and went straight to sleep. Soft peppermint sticks or peppermint tea that has been cooled with just a little bit of sugar works just as well. This has worked for me through numerous kids and it works every time without fail.
Drink Aloe Vera juice, great way to ease the pain, it works almost immediately!
Ginger. It's best if you get a natural ginger ale or get regular and put extra ginger in it your self.
1/2 tsp of baking soda 4 oz of water mixed together does the trick but it tastes really grosss.