Gastroenteritis

Gastroenteritis is an inflammation of the gastrointestinal tract. (Read about "Digestive System") Symptoms include:

• diarrhea (Read about "Diarrhea")
• nausea
• abdominal cramps
• vomiting
• fatigue
• fever
• muscle aches

For healthy adults, gastroenteritis may cause only discomfort and inconvenience. But it can be dangerous in the very ill, the very young and the very old.

The most common cause of gastroenteritis is infection. Infectious gastroenteritis may be caused by viruses, bacteria or parasites. (Read about "Microorganisms")

• Viruses - Viral gastroenteritis is highly contagious. It is also the second most common illness in the United States, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Viral gastroenteritis causes millions of cases of diarrhea each year. Viral gastroenteritis is often mistakenly called "stomach flu," but it is not caused by the influenza virus. (Read about "Influenza") Some of the most common viruses that do cause gastroenteritis include:
  • Rotavirus - typically causes vomiting and watery diarrhea for 3 to 8 days, along with fever and abdominal pain. (Read about "Rotavirus")
  • Adenovirus - occurs mainly in children under the age of 2 years. It causes 5-20 percent of the gastroenteritis in young children, and is the second most common cause of gastroenteritis in this age group. By 4 years of age, 85 percent of all children have developed immunity to the disease.
  • Caliciviruses - cause infection in people of all ages. This family of viruses is divided into 4 types, the noroviruses being the most common and most responsible for infecting people. (Read about "Noroviruses")
  • Astrovirus - also infects primarily infants, young children and the elderly. Astroviruses cause sporadic gastroenteritis in children under 4 years of age and account for about 4 percent of the children hospitalized for diarrhea. Most American children over 10 years of age have antibodies to the virus.
• Bacteria - Bacteria can also lead to gastroenteritis. Examples include:
  • E.coli - Infection with this microorganism often leads to bloody diarrhea, and occasionally to kidney failure. (Read about "Kidney Disease") It's often associated with eating undercooked and/or contaminated ground beef. This is often called "travelers diarrhea." (Read about "E. coli")
  • Shigella - Most who are infected with shigella develop diarrhea, fever and stomach cramps starting a day or two after they are exposed to the bacterium. (Read about "Shigellosis")
  • Salmonella - Salmonella bacteria are usually transmitted to humans by eating foods contaminated with feces. (Read about "Salmonella")
  • Campylobacter - Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain and fever within 2 to 5 days after exposure to the organism. (Read about "Campylobacter")
• Parasites - Some intestinal parasites can also lead to gastroenteritis. Examples include:
  • Giardia lamblia - This parasite is often passed from child to child in day-care centers. It is also spread through contaminated water supplies. (Read about "Giardiasis")
  • Cryptosporidium - Cryptosporidiosis is a diarrheal disease caused by a microscopic parasite, cryptosporidium parvum. It can live in the intestine of humans and animals and is passed in the stool of an infected person or animal. (Read about "Cryptosporidiosis")

Diagnosis, treatment and prevention

In diagnosing gastroenteritis, your doctor will first try to rule out other conditions that could be causing the symptoms, such as Crohn's Disease. (Read about "Crohn's Disease") Lab tests (Read about "Laboratory Testing") may also be run on a sample of feces to determine the specific virus or germ that is causing gastroenteritis.

Treatment, of course, depends on the cause. If it is caused by a parasite, such as with giardiasis and cryptosporidiosis, there are antimicrobial medications that can be used. The Centers for Disease Control and Prevention (CDC) say antibiotics are not useful in many cases. That's because many times gastroenteritis is caused by viruses, which don't respond to antibiotics. (Read about "Antibiotics")

The biggest danger for anyone with gastroenteritis, especially children and seniors, is dehydration as a result of diarrhea. (Read about "Dehydration") This happens if the body loses more fluids and salts (electrolytes) than it takes in. Signs of dehydration include a decrease in urine production (Read about "The Urinary System"), extreme thirst, dry mouth and unusual drowsiness. Severe dehydration is a medical emergency and requires immediate care.

CDC says special oral rehydration fluids can be purchased at drugstores, and can be used according to the package directions. You should ask your pediatrician what's best in your child's case.

If you have any concerns about dehydration or about a child's or your own diarrhea, contact your doctor at once. It's also important to call your doctor if someone with diarrhea is also experiencing any of the following:

• high fever
• blood in stools (Read about "Gastrointestinal Bleeding")
• prolonged vomiting that prevents keeping liquids down

Perhaps the best course is to develop (and help children develop) habits that can reduce the risk of infections that lead to gastroenteritis. The following are suggestions from CDC and the International Food Information Council:

• Wash hands carefully and often. Adults should wash their hands after using the toilet, helping a child use the toilet, diapering a child and before preparing, serving or eating food. Children should wash their hands after using the toilet, after having their diapers changed (an adult should wash infant's or small child's hands) and before eating snacks or meals.
• Disinfect toys, bathrooms and food preparation surfaces frequently, especially if a sick child has been in the home.
• Use diapers with waterproof outer covers that can contain liquid stool or urine or use plastic pants and make sure that children wear clothes over diapers.
• Wash fruits and vegetables thoroughly before eating. Cook meats, fish and poultry thoroughly (Read about "Food Safety")
• Avoid raw eggs; in recipes using eggs that aren't cooked, such as eggnog, you can substitute pasteurized eggs, sold in the grocery dairy case or freezer

Although you can't guarantee you or your family will never get diarrhea or gastroenteritis, you can at least help reduce your risk.

Related Information:

    Animal & Insect Borne Diseases

    Listeriosis

    Food Safety

    Travel and Health