Diarrhea also spelled diarrhoea, happens when the body makes more watery feces than normal. In a baby it is the most general symptom of malnutrition. This means not eating sufficient, or well adequate. Diarrhea can happen in humans as well as most other mammals. Diarrhea is a difficulty everybody is familiar with. It is one of the most general reasons for public to look for medical advice. But it can variety from being a mild, typically temporary circumstance, to one that can threaten life.