Give everybody a once over, males included. The blood may or may not be in the stool just yet. Make sure you are not feeding them something that is staining the poop. Blood appears usually very very dark red or black. If you determine that nobody is bleeding from anywhere and you see blood in the stools, the cocci is a possibility. Dehydration can cause blood in the stool. Even some types of enteritis's can cause blood in the poop. (it is also normal for tiny specks of blood occasionally in poop as they do shed intestinal lining on and off, but it should not be a regular thing).
Cocci usually has them off their feed...not eating much, fluffed up in the corners, very lethargic, eyes closed. Same with enteritis, however with enteritis they tend to constantly drink water where cocci they are off that too.
Use Corid for cocci and Duramycin for enteritis. Both are administered thru the water. Corid for 5 days, Duramycin for 7 days. Use probiotics for a week after treatment to replace good bacteria lost during treatment.