A Friend Is Having Cramps Throughout His Body, Along With

A friend is having cramps throughout his body, along with vomiting, sweating. The cramps come in different parts - legs, feet, hands, arms, and are frequent. Cannot keep any food or liquid down for very long. Have tried water, Gatorade-equivalent, water with cran-raspberry. Also tried Pepto Bismol and that comes back almost immediately. Has not been exposed to anyone with a virus or other illness. There is a lot of stress in his life at the moment; can these things be stress-induced? I'm trying to keep him hydrated thinking that could be a source of the cramping. Any suggestions would be greatly appreciated.