is it very foul smelling? { i know of course it foul lol but extremely like not normal} how old are the pups? those are symptoms of parvo { I just went through this with a litter and all survived so dont freak right away} try and keep them hydrated over night thats the best thing you can do , stop feeding for right now until you see the vet, but fluids are important pups can get dehydrated very fast . offer water or pedialyte or broth , if they wont drink on there own syringe it in atleast a few times through the night. get to the vet right away tomorrow they will do a snap test for parvo and can go from there, if its parvo its best to leave in the vet care so they can put them on IV fluids.
There are lots of other things that can cause this though so it may not be but regardless of what it is runs and vomiting can lead to dehydration fast.
have the pups had any shots ? how old are they? have you fed anything different? and when did symptoms start?