Gastroenteritis (Stomach Flu)
Charles Patrick Davis, MD, PhD
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.
John P. Cunha, DO, FACOEP
John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
- Definition of gastroenteritis
- What causes gastroenteritis?
- What are the most common causes of gastroenteritis?
- What are the symptoms of gastroenteritis?
- Is gastroenteritis contagious?
- Who is at risk for gastroenteritis?
- How is gastroenteritis transmitted?
- How does food become contaminated with gastroenteritis-causing bacteria or viruses?
- How is gastroenteritis diagnosed?
- How is gastroenteritis treated?
- When should I call my doctor for gastroenteritis?
- What are complications of gastroenteritis?
- Can gastroenteritis be prevented?
- What is the prognosis for gastroenteritis?
- Find a local Gastroenterologist in your town
Definition of gastroenteritis
Gastroenteritis (often referred to as the "stomach flu," however, it is not related to the influenza virus. Gastroenteritis is a nonspecific term for various inflammatory problems in the gastrointestinal tract with the most common symptoms and signs being diarrhea, nausea, vomiting, and abdominal pains.
As previously mentioned, although it is not caused by influenza viruses, gastroenteritis is commonly referred to as the "stomach flu" because most people have acute symptoms that last a day or so, and then begin to resolve, like the symptoms of more benign flu strains. In the U.S., less than 2% of the estimated 100 million persons with gastroenteritis symptoms per year ever require hospitalization, but in developing countries it is a leading cause of death, mainly due to dehydration. Severe gastroenteritis can cause dehydration. Also, people with symptoms of diarrhea, bloody diarrhea, fever greater than 101 F (38.33 C) for longer than 5 days, or have severe infection (sepsis), and other problems will be considered to have another disease (for example, shigellosis). Not all doctors agree on the nonspecific term of gastroenteritis so for this article, the parameters are presented that comprise the causes and symptoms that many researchers consider to occur with gastroenteritis.
What causes gastroenteritis?
Infectious agents such as bacteria and viruses are the most frequent causes of gastroenteritis in the US and worldwide. Infections cause diarrhea and other symptoms by causing inflammation of the gastrointestinal (GI) tissue. The infections increase the fluid content in the intestines and colon by changing the gastrointestinal tract's ability to absorb water and by increasing the speed of transit (motility) for things you ingest. This, in turn, causes diarrhea. Infectious agents may physically damage intestinal cells directly or indirectly with secreted toxins.
What are the most common causes of gastroenteritis?
The most prevalent cause of gastroenteritis in the U.S. and the world is Norovirus. It causes about 50% to 70% of viral gastroenteritis while Rotavirus, Astrovirus, Adenovirus, and Sapovirus strains cause most of the other viral gastroenteritis infections. Norovirus was also listed as the leading cause of gastroenteritis in children under 5 years old according to the Centers for Disease Control (CDC).
Bacterial causes of gastroenteritis that occur worldwide are Salmonella, Shigella, Campylobacter Aeromonas, and Escherichia coli (E. coli) strains of bacteria. Other bacteria like Clostridium, Vibrio, Campylobacter, and Yersinia spp can cause outbreaks occasionally.
Parasites such as Giardia, Cryptosporidium, and Entamoeba infections can cause gastroenteritis and occasionally, other parasites have outbreaks such as the Cyclospora outbreak that occurred in 2012 to 2013 in the U.S.
There are many other less frequent causes of gastroenteritis such as food allergies, antibiotics, and toxins. Gastroenteritis symptoms are frequently listed as possible side effects of many medicines.
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