How long viral gastroenteritis, commonly known as the stomach flu, lasts can fluctuate. However, viral gastroenteritis typically lasts between one and three days, though some symptoms can persist for up to ten days in certain cases. This illness causes inflammation of the stomach and intestines and is often marked by symptoms such as watery diarrhea and vomiting. The duration an individual experiences symptoms associated with the illness can vary considerably and may depend on the individual's overall health status, as well as the specific virus responsible for causing the infection, and how quickly treatment and supportive care are administered. Patients may experience varying levels of severity with their symptoms, ranging from mild discomfort to severe dehydration, especially if proper hydration is not maintained. Individuals need to seek out medical assistance if they persist beyond the typical duration or if there are signs of severe dehydration, such as extreme thirst, dry mouth, and lightheadedness.