Yes, it is possible to have gastroenteritis without vomiting or diarrhea. Symptoms such as headache and stomach pain can still be present. To help with these symptoms, you can try taking Tylenol for pain and Gravol for nausea. It is also recommended to eat light foods like soups, bread, brown rice, crackers, toast with butter, and eggs. Avoiding very fatty or sugary foods, such as red meat, can help reduce nausea. Make sure to stay hydrated by taking small sips of liquids every few minutes. If you have any other questions or concerns, feel free to reach out to a healthcare professional for further guidance.