
Gastroenteritis
(Viral Gastroenteritis, "Stomach Flu")
What is viral gastroenteritis?
Gastroenteritis means inflammation of the stomach and
small and large intestines. Viral gastroenteritis is an infection caused by a
variety of viruses that results in vomiting or diarrhea or both. It is often called the "stomach flu," although it is not
caused by the influenza viruses.
What causes viral gastroenteritis?
Many different viruses can cause gastroenteritis, including rotaviruses, noroviruses, adenoviruses, type 40 or 41, sapoviruses, and astroviruses. Viral gastroenteritis is not caused by bacteria (such as
Salmonella or
Escherichia coli) or parasites (such as
Giardia), or by medications or other medical conditions, although the symptoms may be similar. Your doctor can determine if the diarrhea is caused by a virus or by something else.
What are the symptoms of viral gastroenteritis?
The main symptoms of viral gastroenteritis are watery
diarrhea and vomiting although one or the other
symptom may predominate. The affected person may also have headache, fever, and
abdominal cramps ("stomach ache"). In general, the
symptoms begin
1 to 2 days following infection with a virus that causes gastroenteritis and
may last for 1 to 10 days, depending on which virus causes the illness;
however, most episodes last from 1-3 days.
Is viral gastroenteritis a serious illness?
For most people, it is not. People who get viral
gastroenteritis almost always recover completely without any long-term problems.
Gastroenteritis is a serious illness, however, for persons who are unable to
drink enough fluids to replace what they lose through vomiting or diarrhea.
Infants, young children, and persons who are unable to care for themselves, such
as the disabled or elderly, are at risk for dehydration from loss of fluids.
Immune compromised
persons are at risk for dehydration because they may get a more serious illness,
with greater vomiting or diarrhea. They may need to be hospitalized for
treatment to correct or prevent dehydration.
Is the illness contagious? How are these viruses spread?
Yes, viral gastroenteritis is contagious. Outbreaks (in which many
people are affected) occur primarily from eating or drinking contaminated
foods or beverages. The viruses that cause gastroenteritis also are spread through close
contact with infected persons through contamination with stool or vomitus.
How does food get contaminated by gastroenteritis viruses?
Food may be contaminated by food preparers or handlers who have viral
gastroenteritis, especially if they do not wash their hands regularly after
using the bathroom. Shellfish may be contaminated by sewage, and persons who eat
raw or undercooked shellfish harvested from contaminated waters may get
diarrhea. Drinking water can also be contaminated by sewage and be a source of
spread of these viruses.
Next: Where and when does gastroenteritis occur? »
- Colonoscopy - Learn about the colonscopy procedure, what it is, why it is performed, preparation, complications, alternatives and the after effects of the screening exam on MedicineNet.com
- Rectal Bleeding - Rectal bleeding can be a sign of several different conditions including hemorrhoids, anal fisure, colitis, and more.
- Endoscopy (Esophagogastroduodenoscopy, EGD) - Learn about the endoscopy procedure which examines the esophagus, stomach and duodenum to detect gastrointestinal and digestive disorders on MedicineNet.com
Latest Medical News