Viral Gastroenteritis

Gastroenteritis is the medical term for infections causing inflammation of the stomach and intestines. Viruses are common causes of gastroenteritis.

Many infections of the digestive tract are lumped under the term gastroenteritis, commonly referred to as "stomach flu."

Most cases of gastroenteritis are caused by viruses, although the upset also may be caused by toxic substances, antibiotics or other drugs that alter the natural bacterial population of the lower gastrointestinal tract, or a reaction to certain foods.

Bacteria such as salmonella and shigella, and intestinal parasites also may cause gastroenteritis.

Viral gastroenteritis takes two major forms: sporadic and epidemic. The sporadic form of viral gastroenteritis induces vomiting, diarrhea, abdominal discomfort, fever, or a combination of these. However, it differs from the epidemic form in a number of important respects: it primarily affects infants and young children under two years of age, and it induces a range of responses that vary from subclinical infection to mild diarrhea, to a severe and occasionally life-threatening, dehydrating illness.

Epidemic viral gastroenteritis has acquired various names in medical literature including "winter vomiting disease," "acute infectious nonbacterial gastroenteritis ," "epidemic diarrhea and vomiting," "epidemic collapse," and "epidemic nausea and vomiting." In the lay press, it is frequently referred to as "intestinal flu" or "stomach flu." The last two terms are incorrect and should be avoided. The influenza virus does not cause epidemic viral gastroenteritis but instead is responsible for "the flu," a systemic, febrile (causes a fever) disease that predominantly involves the respiratory tract and not the digestive tract in humans.

The primary cause of this problem is the ingestion of food that has been prepared by someone carrying the virus.

The symptoms caused by these infections include fever, nausea, vomiting, abdominal cramping, and diarrhea. When nausea and vomiting are present, they are usually strongest the first 12 to 24 hours and slowly improve thereafter. In addition, diarrhea and cramping may begin during this 24 hour period or immediately afterward.

Diarrhea may last a day or two, or in young children it may last a week or longer. Fever is generally short-lived, lasting one to three days.