Is it possible to have stomach cramps for over 15 hours and not be vomiting but still flu?

While it is possible to have stomach cramps for over 15 hours and not be vomiting and still have the flu, it is not a typical symptom. The flu is a respiratory illness that is caused by the influenza virus. The most common symptoms of the flu are fever, chills, muscle aches, headaches, and fatigue. Vomiting and diarrhea are also common symptoms of the flu, but they are not as common as the other symptoms. If you are having stomach cramps for over 15 hours and you have other flu-like symptoms, it is important to see a doctor to rule out other possible causes.