I treated my 3 month old pullets for cocci after seeing bloody poops. They got Corid in their water for 7 days, (2 tsp/gal) made fresh daily., now on the lower dose for another 1-2 weeks. After this course of treatment they are still having blood in their poops, though it is otherwise normal looking (solid, not liquidy or mucusy) but definitely still looks like blood, some times more than others. I'm mainly judging by the poops under their roosts in the morning, poops in the run seem less bloody/ not bloody but it's harder to spot them and examine out there!
I also saw one quite bloody poo that also maybe had a worm in it, it had a stringy thing at any rate.
Can worms cause blood in the stool? Should I worm them or would that be too hard on them?
Is it possible Corid is not working? I could try to get a different type of cocci med, in fact I think I have some sulfadimethoxine powder though it is expired (I think this is Amprol). I was reluctant to try the powder because I thought that people said it was harsh, especially if they're already having blood in their poops.
BTW, I tried to get a stool test a local vet but they couldn't seem to deal with chicken poo and ended up refunding me. They claimed that it was negative for worms, etc but they seemed very unclear as to whether it was tested for cocci (and maybe the whole thing was messed up).