E coli comes from a drink / food that is kept at the wrong temperature and has been setting to long. E coli is bacterium found in warm blooded animals including humans. E coli are everywhere no matter where you go restaurants, bathrooms, keyboards, etc… There are several strains of E coli such as E. coli O157:H7.
You can become infected after eating at a restaurant or drinking contaminated water. Restaurants do not regularly check their food for the right temperature. It can cause severe diarrhea and nausea and may cause someone to become weak.