Influenza refers to a disease that manifests as cough, fever, and sore throat following human infection by the influenza virus. It is commonly known as the flu or influenza. In addition to respiratory symptoms, the flu may also present with digestive symptoms such as nausea, vomiting, abdominal pain, and diarrhea. Therefore, for flu treatment, one can visit the respiratory department. Of course, in cases of severe symptoms such as high fever, chest tightness, and fatigue, one may also visit the emergency department. However, if the initial diagnosis is predominantly digestive symptoms, it's possible that the gastroenterology department will refer the patient back to the respiratory department for treatment. This requires careful differentiation and exclusion by the doctor before making a diagnosis, so visiting the respiratory or emergency department for flu is appropriate.