Doctor's Notes on Norovirus Infection
Norovirus is a common virus that infects humans. It is the most common cause of gastroenteritis (often referred to erroneously as “stomach flu”) in the US. People get the virus by ingesting food or drink that has been contaminated with small amounts of feces or fluids from infected people, such as occurs with poor handwashing. Foods and water may become contaminated during processing, preparation, or handling.
Characteristic signs and symptoms of norovirus infection are vomiting, nausea, and a watery diarrhea. The symptoms usually last 2-3 days and the go away on their own. Fluid lost through diarrhea and vomiting can lead to associated symptoms of dehydration, and young children and the elderly are most at risk for these complications. Other possible associated symptoms are fever, abdominal cramping, muscle aches, tiredness, and headache.
Stomach Pain : Nausea & Other Causes Quiz

Bowel regularity means a bowel movement every day.
See AnswerREFERENCE:
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.