What is Gastroenteritis?

Gastroenteritis, also known as Stomach Flu or Stomach Virus, is a highly communicable condition that causes an increase in the frequency and water content of the stool as a result of inflammation of the mucous membranes of the stomach and intestinal tract. It is an acute diarrheal illness that causes significant morbidity among young children and older adults, especially in less industrialized nations of the world like Africa, Asia and Latin America. Gastroenteritis often occurs in epidemic outbreaks and the highest incidence is in areas of poor sanitation during the warm months.

The severity of gastroenteritis depends on a person's immune systems and its capability to resist the infection. The recovery period of gastroenteritis will also depend on the causative agent. Gastroenteritis can be spread through contaminated water and food.  Another way of infection is breathing in an airborne virus from an infected person.

What Causes Gastroenteritis?

The causes of gastroenteritis can be viral, bacterial or parasitical. This typically results in a release of a toxin or a poison, which can harm the gastrointestinal tract and causes the increase in fluid production. There are different viruses that can cause gastroenteritis, and they can be acquired through close contact from one person to another, such as rotavirus which commonly affects young children.  Other types of viruses such as adenoviruses, astroviruses, and noroviruses affects both adults and children and is the leading cause of viral gastroenteritis in the United States and in other developed countries.

In bacterial gastroenteritis, it can be acquired through food poisoning via contaminated food and water. Poor sanitation also plays a role which includes Campylobacter, a bacteria that can be found in unpasteurized milk and meats that are not properly cooked. Another popular infection is Salmonella, which can be acquired by people who had contact with reptilian pets or poultry. Escherichia coli (E.coli) are also common and are occasionally responsible for product recalls.

There are even parasites that are often acquired from public swimming pools and from drinking contaminated water.  Lactose intolerance may also cause gastroenteritis as well as some medications such as Nonsteroidal anti-inflammatory drugs (NSAID's), Laxatives, Steroids, Antibiotics, and Caffeine.

Symptoms of Gastroenteritis

There are several symptoms that occur in gastroenteritis that include:

  • Diarrhea
  • Dry Mouth
  • Sunken Eyeballs
  • Fever
  • Headache
  • Abdominal pain
  • Nausea and vomiting
  • Abdominal cramps
  • Loss of appetite
  • Fatigue
  • Body malaise
  • Dehydration
  • Bloody stool


If gastroenteritis is not treated immediately, there may be complications that can occur such as:

  • Chronic diarrhea
  • Reactive arthritides
  • Thrombotic thrombocytopenic purpura or TTP (E coli O157:H7)
  • Guillain-Barré syndrome (Campylobacter organisms)
  • Hemolytic-uremic syndrome
  • Meningitis
  • Arthritis
  • Pneumonia
  • Sepsis
  • Toxic megacolon
  • Persistent diarrhea
  • Malabsorption
  • Transient lactose intolerance

Diagnosis of Gastroenteritis

The history of the patient can provide information related to the potential cause of the illness.

The physician will initially ask several questions to the patient regarding their condition. These will include, but are not limited to:

  • Recent travel to endemic or tropical countries like Asia and Africa.
  • Any exposure to poisons.
  • Medication intake.
  • Recent dietary intake and habits.
  • Recent swimming in possible contaminated pools or water parks.
  • Recent food handling and storage.

There are different tests or assessments that can help diagnose the disease such as:

  • Complete blood count - To check for elevated white blood cells which indicate infection, and to check if there is any electrolyte imbalance.
  • Stool examination and stool culture - The doctor will take a stool sample to check for blood (white blood cells and red blood cells) in the stool and to determine what bacteria is present, as well as to check for the presence of parasites and their eggs.
  • Enzyme-linked Immunosorbent Assay (ELISA) - To check for the presence of rotavirus or giardia.

Treatment of Gastroenteritis

The treatment for gastroenteritis depends on the severity of the condition. Most of the time the patients are advised to stay in their homes until symptoms are relieved. The following are the different treatments and care for gastroenteritis:

  • Fluid therapy focuses on fluid replacement to treat dehydration. The primary treatment in both adults and children is rehydration through the mouth, which replenishes water and electrolytes lost. For patients with fluid volumes severely depleted, and who cannot take anything by the mouth because of vomiting; an intravenous fluid (IV) is given to rehydrate the patient.  Oral rehydration solution (ORESOL) such as Dioralyte, and for children, Rice-Lyte, Resol, Pedialyte, and Rehydrate may be given.
  • Drug therapy focuses on the suppression of the intestinal motility, controlling nausea and vomiting as well as treating the underlying cause of infection. These drugs includes:
    • Antiemetic - Drugs used to treat nausea and vomiting.
      • Ondansetron (Zofran)
      • Promethazine (Phenergan)
      • Trimethobenzamide (Tigan)
      • Prochlorperazine (Compazine)
  • Antidiarrheal agents - Drugs used to treat diarrhea.
    • Loperamide (Imodium)
  • Antibiotics - Drugs used to treat infection.
    • Rifaximin (Xifaxan, RedActiv, Flonorm)
    • Ciprofloxacin (Cipro)
    • Trimethoprim-sulfamethoxazole (Bactrim)
  • Diet therapy is also a common treatment. Foods or drinks high in sugar should be avoided. The practice of withholding food is not recommended. The BRAT diet (bananas, rice, apple sauce, toast and tea) is also not recommended.

Prognosis of Gastroenteritis

The prognosis of gastroenteritis is very good since there are available treatments that can cure the condition.

Preventing Gastroenteritis

There are different ways in preventing gastroenteritis. These include:

  • Hand washing
  • Vaccination
  • Disinfecting and cleaning the toilet regularly
  • Not sharing utensils and towels with other people
  • Proper food storage
  • Clean eating utensils properly
  • Avoid eating street foods
  • Cook meat properly
  • Avoid drinking dirty water or tap water
  • Dispose soiled linens or items properly
  • Avoid traveling to countries that have a high incidence of gastroenteritis
  • Avoid foods, drinks, and medications that cause gastroenteritis

Living with Gastroenteritis

People living with gastroenteritis should seek medical help to determine what causes the disease. Always follow your doctor's recommendations and go to all your medical checkups. For babies, parents should observe any abnormal changes in stool or appetite and assess for any unusual symptoms.

Last Updated: Saturday, April 14, 2012