Queen Elizabeth II has been hospitalized with an apparent stomach condition that is showing symptoms of gastroenteritis.

What is gastroenteritis?

The condition is characterized by the inflammation of the stomach and small intestine which may cause a combination of vomiting, diarrhea and abdominal pain.

The virus can be transmitted after coming into contact with contaminated food or water, or through contact with other individuals who are infectious.

In England, the two most common causes of gastroenteritis in adults is food poisoning and the norovirus -- a common winter bug that typically afflicts between 600,000 and one million Britons yearly.

How long do the symptoms last?

The symptoms of gastroenteritis -- vomiting and diarrhea -- usually pass after one or two days, although they can be more severe in older or otherwise vulnerable people. Dehydration is a common complication.

What is the treatment?

Gastroenteritis typically does not require medication. Rather, the preferred treatment is oral rehydration therapy.