causes of a upset stomach
An upset stomach is characterized by swelling (inflammation) of the stomach lining and intestines. It is sometimes caused by a virus, although it may also be due to a parasite, or due to bacteria like salmonella or E. coli. In some cases, an upset stomach is the result of an allergic reaction to a certain type of food. It also may be caused by an irritation. Sometimes this happens from consuming too much alcohol or caffeine. Eating too many fatty foods â or too much food in general â may also cause an upset stomach.