Consider a small amount of Lemon juice with all meals diluted with 4-5oz water or Aloe.
My wife and I cannot count the times we have picked up a stomach virus from eating in restaurants. Especially when we travel. In addition its known from my research bring a small bottle of Cayenne 515mg. 40,000 heat units and take until symptom are gone. I know how it works because its pretty strong.
Example! While I was in Orlando area we ate at a well known buffet restaurant. I ate turkey that may have been sitting to many hours on the line of foods. It didn't take long 3 hours later I could not stand and my head was spinning and stomach pain. I'm so glad we came across this remedy. 20 minutes later I started to feel better. And the next day I was fine. But, still took the same course of action.