Question: what is the incubation period for the stomach flu after exposure?
Answer: Incubation Period, Diagnosis/Symptoms and Immunity After initial (first) exposure, a person will usually get the stomach flu within 12-48 hours. The stomach flu is diagnosed based mostly on symptoms, including nausea, vomiting, diarrhea, muscle aches, abdominal cramps, and no fever or a low-grade fever.