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Viral Gastroenteritis

(aka 'The Stomach Flu')

Viral gastroenteritis is second only to the common cold as the most frequent cause of illness in the United States. It's often called 'stomach flu,' but isn't actually caused by influenza viruses.

The disease is transmitted through contaminated food and water and by person-to-person contact. An infected person’s feces and vomit contain the viruses; poor hygiene and sanitation practices help them spread easily. Common food sources include salads and shellfish, particularly raw or undercooked clams and oysters; ill food handlers can spread the viruses to other foods as well. Municipal pools, lakes and wells are frequent sources of contaminated water.

Symptoms begin within 24 – 48 hours of exposure and include nausea, vomiting, abdominal cramping and diarrhea; there may be low-grade fever, headache and body aches. They typically last between 18 and 24 hours, but occasionally as long as 48 – 60 hours. Because the infection is viral, antibiotics will not shorten its course.


Good hand hygiene is the most effective way to prevent the spread of infection. Hands should be cleaned after touching any soiled item, including faucets, handles and doors; before and after preparing food and eating; after using the bathroom, after handling garbage or dirty laundry; after touching animals; and after blowing the nose or sneezing.

When a sink is available, use water and plain or antimicrobial soap; rub hands together for 15 – 30 seconds, paying attention to the fingernails, between fingers and wrists. Rinse thoroughly and dry with a single-use towel.

Alcohol-based hand rubs such as Purell are a good alternative if a sink isn’t available. Spread the sanitizer over the entire surface of hands, fingers, and wrists, rubbing until dry. Hand rubs are available as wipes or small sizes of liquid that are easy to carry.


Treatment is aimed at preventing dehydration from vomiting and diarrhea. Drink small amounts of fluids frequently, as tolerated. If vomiting occurs, give the stomach time to rest before trying fluids again.
For otherwise healthy persons who aren’t severely dehydrated, fluids can include sports drinks such as Gatorade; diluted fruit juice; flavored soft drinks like ginger ale; broth and soup. Saltine crackers are a good accompaniment.

Oral rehydration fluids offer water, sugar and salt. To make your own, add ½ teaspoon salt, ½ teaspoon baking soda and 4 tablespoons of sugar to one quart of water. Cera-lyte is a rice-based rehydration solution available over-the-counter.

Solids can be eaten as tolerated; the BRAT diet – bananas, rice, applesauce, tea and toast – is easy to remember. Boiled starches, like potatoes, noodles, oat or wheat cereals, along with boiled vegetables, may also be good choices. It’s common to have problems tolerating milk and other dairy products immediately after a diarrheal illness.


Pepto-Bismol (bismuth subsalicylate) is generally safe, as long as a person doesn’t have sensitivity to aspirin or aspirin-like products. Take two tablespoons of liquid or two tablets every 30 minutes to one hour, up to eight doses in 24 hours, to help abdominal cramps and diarrhea.

Imodium AD (loperamide) dosage is two tablets (4 mg.) initially, and then one tablet (2 mg.) after each unformed stool, not to exceed eight tablets per day. It shouldn’t be used for more than two days, or if there is bloody diarrhea.

Probiotics containing lactobacillus are moderately expensive, but have been shown to be effective in viral diarrheal illnesses.

When to get help

Call the UHS Triage Advice Nurse, (413) 577-5229, if you have questions, concerns or if you experience:

  • bloody diarrhea;

  • moderate to severe dehydration, associated with dizziness, fainting, or near-fainting;

  • severe abdominal pain lasting more than a couple of hours that isn’t relieved by self-treatment; or

  • fever greater than 102 F, or fever over 101 F lasting more than three days.