[header] How to identify causes of diarrhea [title] Determine whether you might have a virus. [step] Viruses are a common cause of diarrhea that are passed from person to person through handshakes, shared utensils, and touching the same surfaces. Children attending school or going to daycare are at increased risk of getting a virus that can cause bacteria. 
If you or your child recently spent time in a public area trafficked by a lot of other people, you may have picked up a virus. [substeps] Viral gastroenteritis is a viral infection in the small intestines and stomach.