Gastroenteritis, also known as infectious diarrhea, gastric flu, or stomach bug. It is inflammation of the lining of the intestines caused by a virus, bacteria or parasites. The cause is often a norovirus infection. It spreads through contaminated food or water, and contact with an infected person. The best prevention is frequent hand washing soap, drinking clean water, proper disposal of human waste, and breastfeeding babies instead of using formula. The most common problem with gastroenteritis is dehydration and other symptoms are, abdominal pain, vomiting, headache, fever and chills. Gastroenteritis can be due to infections by viruses, bacteria, parasites, and fungus. The most common cause is viruses. Rotavirus is the main cause of severe condition in children while In adults, norovirus and Campylobacter are common.