The best prevention is to avoid antibiotics that are not needed. Proper hand washing when caring for the sick may help prevent cases due to infection.
Most people recover without any long-term effects. Diarrhea that lasts a long time can lead to salt imbalances and dehydration. Rarely, a hole forms in the bowel, or the bowel becomes enlarged. This can lead to severe infection and even death.
There are usually no risks to others. If infection is causing the diarrhea, it could be passed to others.