Viral gastroenteritis is an intestinal infection that includes signs and symptoms such as watery diarrhea, stomach cramps, nausea or vomiting, and sometimes fever.The most common way to develop viral gastroenteritis - often called stomach flu - is through contact with an infected person or by consuming contaminated food or water. If you're otherwise healthy, you'll likely recover without complications. But for infants, older adults and people with compromised immune systems, viral gastroenteritis can be deadly.There's no effective treatment for viral gastroenteritis, so prevention is key. Avoid food and water that may be contaminated and wash your hands thoroughly and often.