Norovirus is one of the most common causes of acute gastroenteritis, often referred to as the "stomach flu.” While highly contagious, norovirus tends to move quickly through the body, meaning symptoms usually appear soon after exposure. Understanding the norovirus incubation period and early warning signs can help you recognize infection early, reduce spread, and know when medical care is necessary. For same-day norovirus treatment, visit the walk-in clinic at AFC Urgent Care Denver Five Points ...