A viral infection, such as viral gastroenteritis, usually lasts less than a week. However, many different illnesses are commonly referred to as "a virus," and the length of time can vary depending on the specific condition.
To understand how long a virus may last, it is important to see a doctor so the exact cause of the symptoms can be identified.
When a virus causes diarrhea, nausea, and/or vomiting, medical care should be sought if there are signs of dehydration or if vomiting continues for an extended period. In these cases, doctors often recommend IV fluids to help with recovery.