What causes gastroenteritis (stomach flu)?
There are many causes of stomach flu (gastroenteritis), including bacteria such as E. coli, Camphylobacter, Shigella, and Salmonella. Viruses can also cause stomach flu and are responsible for 30 percent to 40 percent of gastroenteritis cases in children. Common stomach flu viruses include norovirus or Norwalk-like virus, adenovirus, rotavirus, calicivirus, and astrovirus. Stomach viruses are notorious for spreading rapidly because of poor hand washing. While not as common, parasites such as giardia and cryptosporidium can cause severe diarrhea and dehydration. Water-borne parasites are common in underdeveloped parts of the world that have unsanitary water supplies. It is recommended that travelers stick to bottled water to avoid water-borne parasites — a potential cause of gastroenteritis. Some foods may irritate your stomach and also cause gastroenteritis. Reaction to dairy products in someone with lactose intolerance is the most common example. Severe reactions to seafood is anothe
