Gastroenteritis

Gastroenteritis is an inflammation of the lining of the intestines caused by a virus, bacteria or parasites. Gastroenteritis can also be caused by ingestion of chemical toxins or drugs.

The cause is more often due to norovirus infection. It is spread through food or water that has been contaminated as well as through contact with an infected person.

Symptoms of gastroenteritis include nausea, diarrhea, abdominal cramping, vomiting, headache, fever and chills.

Most people can recover without receiving treatment and most people will get better in 1 to 3 days.

Antibiotics will not help if you have norovirus illness since antibiotics fight against bacteria, not viruses. However, antibiotics can be used to treat gastroenteritis caused by some bacteria.

Antiparasitic medications, such as metronidazole and nitazoxanide, can be given to treat parasitic infections.

The most common problem associated with gastroenteritis is dehydration. Dehydration can occur if you do not drink enough fluids to replace what is lost through vomiting and diarrhea. Babies, young children, the elderly and people with weak immune systems are at a higher risk for dehydration.

Symptoms of gastroenteritis include:

• nausea
• diarrhea
• abdominal cramping
• vomiting
• headache
• fever
• chills
• loss of appetite and weight loss

Gastroenteritis may be caused by viruses, bacteria, or parasites. Gastroenteritis can also be caused by ingestion of chemical toxins or drugs.

Viruses:

The cause of gastroenteritis is mostly due to norovirus infection. Norovirus, can spread quickly especially in crowded, closed places like nursing homes, daycare centers, schools, and cruise ships. Norovirus can also cause outbreaks in restaurants and if food is contaminated.

Other possible causes include:

• Rotavirus
• Astrovirus 
• Enteric adenovirus

Since the viruses are found in the vomit and stool of infected people, you can get gastroenteritis by:

• Eating contaminated food or liquids
• Touching your mouth after touching a contaminated object
• Having direct contact with a person who is infected

People with norovirus are contagious from the time they begin feeling sick until at least 3 days after they recover. Some people may be contagious for even longer.

Bacteria:

Salmonella and Campylobacter are the most common bacterial causes of diarrhea in the United States. Both infections are most frequently acquired from undercooked poultry as well as with unpasteurized milk.

Other possible causes include:

• Shigella
• Escherichia coli (E. coli)

Parasites:

• Giardia intestinalis is more common in cold climates but occurs in every region of the United States and throughout the world
• Cryptosporidium parvum

Chemical Gastroenteritis

Gastroenteritis may result from ingesting chemical toxins such as poisonous mushrooms or by certain kinds of exotic seafood. Gastroenteritis can also be caused by ingesting water or food contaminated by chemicals such as arsenic, lead, mercury, or cadmium. In addition, eating large amounts of acidic foods, such as citrus fruits and tomatoes, can cause gastroenteritis in some people.

The diagnosis of gastroenteritis is usually obvious from the symptoms alone, but the cause often is not.

Your doctor may ask certain questions such as:

• Have any of your family members or coworkers been sick with similar symptoms?
• Have you traveled to a foreign countries?
• Have you taken antibiotics recently?

Often gastroenteritis may be able to be traced to contaminated water or inadequately cooked, spoiled, or contaminated food, such as raw seafood.

If the symptoms are severe or last for more than 48 hours, your doctor may order stool samples. Stool samples may be cultured and examined in a laboratory for white blood cells and bacteria, viruses, or parasites.

If the symptoms continue beyond a few days, your doctor may want to examine the large intestine with a sigmoidoscope (a flexible viewing tube used to view the lower part of the digestive tract) to determine whether the person has a disease such as ulcerative colitis.

The health care provider will look for signs of dehydration.

Signs and symptoms of dehydration may include:

• Dry or sticky mouth
• Feeling Tired
• Urinating less often than usual
• Dark colored urine
• Markedly sunken soft spots (fontanelles) on the top of an infant's head
• No tears

Most viruses and bacteria are passed from person to person by unwashed hands. To prevent viral gastroenteritis, handle food properly and wash your hands thoroughly after using the toilet.

Infants and other people with a weakened immune system should not be exposed to reptiles, birds, or amphibians, because these animals typically carry Salmonella bacteria.

For infants starting at age 2 months, vaccination to prevent severe rotavirus infection is recommended.

Steps to reduce your risk of getting gastroenteritis, include:

• Wash your hands often, especially after going to the bathroom and when you are working with food
• Clean and disinfect kitchen surfaces, especially when working with raw meat or eggs
• Keep raw meat, eggs, and poultry away from foods that are eaten raw
• Drink bottled water and avoid ice cubes when traveling, especially in developing countries

Norovirus can lead to dehydration. The best way to prevent dehydration is to drink plenty of liquids.

Most people can recover without receiving treatment and most people will get better in 1 to 3 days.

There is no vaccine to prevent norovirus infection. Antibiotics will not help if you have norovirus illness since antibiotics fight against bacteria, not viruses.

However, antibiotics can be used to treat gastroenteritis caused by some bacteria, such as Campylobacter, Shigella, and Vibrio, are the cause, and for people who have traveler's diarrhea. Some bacteria are naturally found in the body and help the growth of good bacteria (probiotics). Your doctor may recommend the use of probiotics, such as lactobacillus, which can be found in yogurt. Probiotics may shorten the duration of diarrhea (perhaps by less than a day).

Antiparasitic medications, such as metronidazole and nitazoxanide, can be given to treat parasitic infections.

Get plenty of bed rest and drink an adequate amount of fluids. The goal of treatment is to prevent dehydration by replacing fluids and electrolytes lost through diarrhea or vomiting. Babies, young children, the elderly and people with weak immune systems are at a higher risk for dehydration.

• Try to drink extra fluids between meals
• Use electrolyte and fluid replacement solutions or freezer pops in younger children
• Avoid use of fruit juice, caffeinated beverages, and sodas or cola, since these contain a lot of sugar. As a result, this may make diarrhea worse, and they don't replace lost minerals.

People with diarrhea who can't drink fluids because of nausea may need intravenous (directly into a vein) fluids.

Before considering giving or taking an over the counter anti-diarrheal medication, talk to your doctor. Based on your situation, your doctor may prescribe or recommend an anti-diarrheal medication.

In addition, tell your doctor if you take water pills (diuretics). Your doctor may advise you to stop taking your water pill for a short time.

Most people can recover without receiving treatment and most people will get better in 1 to 3 days.

Young children, the elderly, and people who have a suppressed immune system are at the highest risk for dehydration and in turn severe gastroenteritis.