When an infection moves into the gastrointestinal tract, the symptoms mirror food poisoning (food poisoning is just a gastrointestinal infection, also known as gastroenteritis, acquired by eating food contaminated with bacteria). Nausea, diarrhea, vomiting and dehydration are the result. It can be devastating to a healthy person, potentially fatal to someone who's already battling other health problems in a hospital.
According to the World Health Organization, gastroenteritis is the most common hospital-acquired infection in children, who are typically affected by rotavirus. Adults who contract gastroenteritis in a hospital are often infected by Clostridium difficile [source: WHO]. C. difficile is particularly dangerous since the bacterial strain has become resistant to many antibiotics.
Maintaining a sterile environment in the hospital remains the key to preventing these infections, but hospitals also have to consider the food they serve to patients, as well as the proper handling of any materials a patient might ingest.