GASTROENTERITIS SYMPTOMS

The main symptom is diarrhea. (The term "stomach flu" owes much of its popularity to the fact that people don't like to say they have diarrhea.) If caused by an infection, the diarrhea usually begins within a day or two of picking up the germ and lasts up to 10 days. Nausea, vomiting, headache, or abdominal pain often accompanies diarrhea, which doctors define as having more than two loose bowel movements in a day.