Gastroenteritis can affect one person or a group of people who all ate the same food or drank the same water. The germs may get into your system directly from food or water or by way of objects such as plates and eating utensils. They can also be passed from person to person with close contact.
Viral gastroenteritis is a leading cause of severe diarrhea in both adults and children. Many types of viruses can cause gastroenteritis. The most common ones are:
Norovirus (Norwalk-like virus) is common among school-age children. It may also cause outbreaks in hospitals and on cruise ships.
Rotavirus is the leading cause of severe gastroenteritis in children. It can also infect adults who are exposed to children with the virus, and people living in nursing homes.
People with the highest risk for severe gastroenteritis include young children, the elderly, and people who have a suppressed immune system.
Symptoms most often appear within 4 to 48 hours after contact with the virus. Common symptoms include:
The health care provider will look for signs of dehydration, including:
Dry or sticky mouth
Lethargy or coma (severe dehydration)
Low blood pressure
Low or no urine output; concentrated urine that looks dark yellow
Markedly sunken soft spots (fontanelles) on the top of an infant's head
Tests of stool samples may be used to identify the virus that is causing the sickness. Most of the time, this test is not needed for viral gastroenteritis. A stool culture may be done to find out if the problem is being caused by bacteria.
The goal of treatment is to prevent dehydration by making sure the body has enough water and fluids. Fluids and electrolytes (salt and minerals) that are lost through diarrhea or vomiting must be replaced by drinking extra fluids. Even if you are able to eat, you should still drink extra fluids between meals.
Older children and adults can drink sports beverages such as Gatorade, but these should not be used for younger children. Instead, use the electrolyte and fluid replacement solutions or freezer pops available in food and drug stores.
Do NOT use fruit juice (including apple juice), sodas or cola (flat or bubbly), Jell-O, or broth. These liquids do not replace lost minerals and can make diarrhea worse.
Drink small amounts of fluid (2 - 4 oz.) every 30 - 60 minutes. Do not try to force down large amounts of fluid at one time, which can cause vomiting. Use a teaspoon or syringe for an infant or small child.
Babies can continue to drink breast milk or formula along with extra fluids. You do NOT need to switch to a soy formula.
Try eating small amounts of food frequently. Foods to try include:
Cereals, bread, potatoes, lean meats
Plain yogurt, bananas, fresh apples
If you have diarrhea and are unable to drink or keep down fluids because of nausea or vomiting, you may need fluids through a vein (IV). Infants and young children are more likely to need IV fluids.
Parents should closely monitor the number of wet diapers an infant or young child has while sick to watch for signs of dehydration.
People taking water pills (diuretics) who develop diarrhea may be told by their health care provider to stop taking the diuretic during the acute episode. However, DO NOT stop taking any prescription medicine without first talking to your health care provider.
Antibiotics do not work for viruses.
You can buy medicines at the drugstore that can help stop or slow diarrhea.
Do not use these medicines without talking to your health care provider if you have bloody diarrhea, a fever, or if the diarrhea is severe.
Do not give these medicines to children.
For most people, the illness goes away in a few days without treatment.
Rotavirus causes severe gastroenteritis in infants and young children. Severe dehydration and death can occur in this age group.
When to Contact a Medical Professional
Call your health care provider if diarrhea lasts for more than several days or if dehydration occurs. You should also contact your health care provider if you or your child has these symptoms:
Most viruses and bacteria are passed from person to person by unwashed hands. The best way to prevent viral gastroenteritis is to handle food properly and wash your hands thoroughly after using the toilet.
Vaccination to prevent severe rotavirus infection is recommended for infants starting at age 2 months.
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Jenifer K. Lehrer, MD, Department of Gastroenterology, Frankford-Torresdale Hospital, Aria Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.