Jackie,
I'm not sure what you mean by "nutritional scours." Does the calf have a liquid stool? Is he humped up and looking like he doesn't feel well, or is he eating & playing normally?
I don't know if there is a bacteria, virus or parasite that can cause white stools in calves, but I can tell you what happened to us once. Our calves were healthy & eating normally, had no diarrhea, but their stools were white. After a couple of weeks, I finally discovered the cause. They had found a bag of cement in a shed, and could just get their heads in far enough to lick the cement. We removed the broken bag of cement and no more white stools! Hope yours is as simple a solution.
Rafter L Murray Greys