Short answers, pulled from the story.
Gastroenteritis is an inflammation of the gastrointestinal tract, including the stomach and intestine. Its main symptoms are diarrhea, vomiting, and abdominal pain, sometimes with fever, lack of energy, and dehydration. It typically lasts less than two weeks.
Gastroenteritis is usually caused by viruses, with rotavirus the most common cause of severe disease in children and norovirus common in adults. Bacteria such as Escherichia coli and Campylobacter, along with parasites and fungi, can also cause it. It spreads through improperly prepared food, contaminated water, or close contact with an infected person.
The primary treatment for gastroenteritis is rehydration, usually through oral rehydration solution made of water, salts, and sugar. Severe cases may require intravenous fluids or fluids given by nasogastric tube. Zinc supplementation is recommended for children, and antibiotics are generally not needed.
In 2015, there were two billion cases of gastroenteritis resulting in 1.3 million deaths globally. Children and people in the developing world are affected the most. More than 450,000 of these deaths are due to rotavirus in children under five.
Gastroenteritis can be prevented through hand washing with soap, drinking clean water, proper disposal of human waste, and breastfeeding babies instead of using formula. Hand washing with soap reduces rates by as much as 30%. The rotavirus vaccine was recommended by the World Health Organization in 2009 for all children globally.
In Canada and the United States, gastroenteritis is often called "stomach flu" even though it is not related to influenza. It also carries colloquial names such as "Montezuma's revenge," "Delhi belly," and "la turista." The term gastroenteritis was first used in 1825.