Green pasture scours

I just turned does out to green pastures, some have developed the runs, it's a dark green. They were wormed the week before the turn out. The pasture is mostly fescue and clover. They have access to a dry feed pellet as well. They just aren't eating much other than greens.

Is there anything that can be put in the water to help clean it up? Any other suggestions?

Thanks for the reply, one pen has started to clean up