Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Gastroenteritis, as defined above, has many causes, but the most frequent
causes are viral and bacterial. Other causes vary greatly, such as parasites, toxins,
food allergies, and medications. Many of the causes of gastroenteritis actually
go on to develop additional gastrointestinal symptoms that are considered
specific diseases themselves. The incidence of deaths due to gastroenteritis has
been recently shown to be increasing. The two major causes of deaths are
attributed to C. difficile, and Norovirus. The following lists the major causes of
gastroenteritis, and also lists the diseases that have symptoms of
gastroenteritis as part of their specific disease process; this list is not
all-inclusive but does include the large majority of causes of gastroenteritis
that are encountered worldwide.
Norovirus: causes about 50% to 70% of all gastroenteritis in adults, the
most common cause of gastroenteritis in the US, and second most common cause of
death due to gastroenteritis.
Rotavirus: common cause of diarrhea in infants, occasionally producing
Sapovirus: common cause of mild gastroenteritis in children
Clostridium difficile: bacterial overgrowth and toxin production
due to antibiotic suppression of competing intestinal bacteria; disease -
C. difficile toxin production; this organism causes the highest number
of deaths due to gastroenteritis, mainly in the elderly, over the age of 65