From what I understand of ringworm, it's usually local to an area. It's a skin fungus (my neighbor recently had it.. Got it from a cat that was in the area). I don't believe it should explain the rash on your legs or the diahrea. Probably best to go see the doc to be sure. If it were ringworm, you would still want to go to the doc so they can give you prescription strength anti-fungal meds.