I had a 1 week old pooping blood. She wasn't eating or drinking and acting very lethargic. I gave her SULMET mixed in water and gave it to her carefully through an eye dropper. It's to treat Cocci. I was able to get it from my local feed store and mix it into the drinking water....follow the directions on the bottle. Do it sooner than later, because it's highly contagious to the other chicks and deadly if left untreated. Once they are on the medication it should clear up very quickly. Are you giving them medicated feed? It's good to give them this till they're 8 weeks old as a preventative. Good luck!