Follow up question.
I started my girls on Corid immediately on 3/31 and gave it for 5 days as per @Eggcessive's post. Everything was great, no signs of bloody stool from anyone.
However, today one of them had a stool that looked like it had blood mixed into it. They're 4 weeks old on 4/17 and haven't been exposed to any other chickens, they're in our house, in a brooder tent.
Is it possible that this is Coccidia again or could it just be shedding intestinal lining? Unfortunately I didn't get a photo of the stool, but it wasn't frank blood like the previous stool was. Also, this is not the same chick as the first time.
ETA: They are all eating, drinking, and acting normally, no puffing or sleepiness.
Thank you for any help!