Sally,
What colour was the Gatorade? That could change the colour too...salmon or tomato soup would make it reddish or light brown...Blood is stool can make it black but so can other stuff that we eat with food colouring like licquorish or blue jujubes.
Mel,
Have you eaten any raw foods lately like sushi? Undercook chicken or meat? Could be pouchitis or it could be something else like a nasty bacteria from foods or some new meds that you have taken...you need to be very careful because dehydration is a serious problem with runny pouches...have you tried anything to slow it down like lomotil or gravol? The fact that you say that it is starting higher up than the pouch and rushing down makes me think of some sort of food poisioning or stomach flu.
Please be very careful, push fluids, salts and glucose (honey is fine if you can handle it) and please call your doctor!
Sharon