We’ve all experienced having an upset stomach. Feeling nauseous, bloated, or even pain around your stomach can be very unpleasant. However, an upset stomach can have various different causes. Indigestion is a common cause of a mildly upset stomach; however, if you’re feeling very sick and experiencing severe symptoms like vomiting or diarrhea, you may have a case of food poisoning. This article will review how to tell whether your stomach upset is ...