Overview
Diarrhea is very common: In Germany, for instance, adults get it once a year on average, and it is even more common in children. It is usually caused by viruses, the most common of which are the highly contagious norovirus and rotavirus. Infectious diarrhea can also come from bacteria such as Salmonella or Campylobacter.
In normal cases of diarrhea, you can usually just replace the fluids you lose and wait until the infection goes away. But more severe or longer lasting diarrhea needs to be treated because it can lead to the loss of dangerously high levels of fluid and salt, especially in young children and older people.
