I would just get the Corid or Ampromed from the cattle section of your feed store right away. Your vet however could do a fecal examine and confirm the coccidiosis. Buttermilk or a small amount of milk mixed with chick feed will help coat the GI tract until you get meds, but hurry. Are you...
I would get some Corid (amprollium) or Ampromed and treat them all for 5 days for coccidiosis. Dosage is 1.5 tsp of powder (or 2 tsp of liquid Corid) to a gallon of water, change water daily. Give vitamins and probiotics after finishing Corid. There doesn't have to be blood in the poop. Here...