E. coli is a common type of bacteria that can get into food, like beef and vegetables. E. coli is short for the medical term Escherichia coli. The strange thing about these bacteria — and lots of other bacteria — is that they're not always harmful to you.

E. coli normally lives inside your intestines, where it helps your body break down and digest the food you eat. Unfortunately, certain types (called strains) of E. coli can get from the intestines into the blood. This is a rare illness, but it can cause a very serious infection.

Someone who has E. coli infection may have these symptoms:

bad stomach cramps and belly pain
vomiting
diarrhea, sometimes with blood in i