My bandmates and I had day jobs painting signs, and then we played music at night. We drank too much and didn't eat enough good food. Our systems were so thrown off-kilter that we all developed bad cases of diarrhea. We honored our affliction by calling the band Three Squirts in the Fountain. The Dire Discomfort Everyone knows what diarrhea is.
Many serious diseases can cause it.
And infectious diarrhea, caused by viruses or bacteria, still ranks as a leading killer of Third World children. The most important thing to do for diarrhea is to drink fluids, but a lot of people do just the opposite. They cut down in the mistaken belief that refraining from drinking fluids will help the body stop producing them. How well I remember one of our ecotourists at Machu Picchu. She was so convinced that her diarrhea was caused by the water that she refused to drink any.