Stomach Bug 2024 Lasting A Long Time. The stomach flu (norovirus) is an acute form of gastroenteritis, or inflamed stomach or intestinal lining caused by a virus, bacteria or parasite. Health officials are tracking an increase in norovirus, which is more commonly known as the highly contagious 'stomach bug'.

People with weaker immune systems may have a harder time. Depending on the cause, a stomach bug can linger for up to 10 days.