The last common symptom of gastroenteritis to discuss is running out of the water. This symptom is called dehydration by the medical experts. This symptom arrives after the first primary signs: diarrhea and vomiting. It happens because of the attempts to recover from the infection. That is why doctors can advise nothing else than double the water consumption during a day. It is easy to define whether the amount of water in your organism is enough. The lack of it leads to the symptoms like red eyes, exhaustion, light head, or dry skin and mouth.