What is gastroenteritis?
Gastroenteritis is an
inflammation of the gastrointestinal tract (the pathway responsible
for digestion that includes the mouth, esophagus, stomach, and
intestines). Gastroenteritis is also sometimes referred to as
"stomach flu," even though it is not related to influenza.
What causes gastroenteritis?
Gastroenteritis can be
caused by viral, bacterial, or parasitic infections. Viral
gastroenteritis is highly contagious and is responsible for the
majority of outbreaks in developed countries.
Common routes of infection include:
- Food (especially seafood)
- Contaminated water
- Contact with an infected person
- Unwashed hands
- Dirty utensils
In less developed countries, gastroenteritis is more often
spread through contaminated food or water.
What are the symptoms of gastroenteritis?
The main
symptom of gastroenteritis is diarrhea. When the colon (large
intestine) becomes infected during gastroenteritis, it loses its
ability to retain fluids, which causes the person's feces to
become watery. Other symptoms include:
- Abdominal pain or cramping
- Nausea
- Vomiting
- Fever
- Poor feeding (in infants)
- Unintentional weight loss (may be a sign of dehydration)
- Excessive sweating
- Clammy skin
- Muscle pain or joint stiffness
- Incontinence (loss of stool control)
Because of the symptoms of vomiting and diarrhea, people who
have gastroenteritis can become dehydrated very quickly. It is very
important to watch for signs of dehydration, which include:
- Extreme thirst
- Urine that is darker in color
- Dry skin
- Dry mouth
- Sunken cheeks or eyes
- In infants, dry diapers (for more than 4-6 hours)
How common is gastroenteritis?
Because
gastroenteritis is so similar to diarrhea, and because so many
cases do not require hospitalization, it is difficult to determine
how many cases of gastroenteritis occur per year. Worldwide, it is
estimated that three to five billion cases of acute diarrhea (which
can be caused by many other diseases besides gastroenteritis) occur
per year, with about 100 million cases in the United States
(roughly one to 2.5 cases of diarrhea per child). Gastroenteritis
is estimated to cause about 5 to10 million deaths per year
worldwide, and about 10,000 deaths per year in the United
States.
Who is at risk for gastroenteritis?
Anyone can get
the disease. People who are at a higher risk include:
- children in daycare
- students living in dormitories
- military personnel, and
- travelers
People with immune systems that are weakened by disease or
medications or not fully developed (i.e., infants) are usually
affected most severely.
How is gastroenteritis diagnosed?
The doctor will
take a medical history to make sure that nothing else is causing
the symptoms. Also, the doctor might perform a rectal or abdominal
examination to exclude the possibilities of inflammatory bowel
disease (e.g., Crohn's disease) and pelvic abscesses (pockets
of pus). A stool culture (a laboratory test to identify bacteria
and other organisms from a sample of feces) can be used to
determine the specific virus or germ that is causing
gastroenteritis.