I would run Corid through their water immediately... if nothing else, as a precaution. I see an awful lot of bright red in there, and while it COULD be intestinal shedding, there's quite a bit of it, and it's really bright.
Treat your entire flock with it as soon as possible!
1.5 teaspoons powder OR 2 teaspoons liquid per gallon of water, 5-7 days, and make sure it's the ONLY water they can access during treatment.
Hopefully, the red will clear up.
I totally agree.