redness in poop

My baby chicks are about 2 weeks old by now and they're doing just fine but
this morning i saw something strange as I went to change their water, as usual one of the chicks had dropped the temperature & humidity display in the corner of the brooder and had pooped on it as well but what caused concern for me was that as I scraped the dry poop off it had left red mark behind on the display and upon inspecting it closely the poop seemed red itself too :(

I knew blood in poo was a symptom of cocci so I put everything aside and got all of them out one by one into a separate box and waited until they pooped, after all 6 samples were ready I proceeded in examining them closely and out of the 6, 4 samples were normal but the other 2 had a bit of red/orange in it but the whole thing wasnt like that

I got the 2 chicks with red/orange-ness in the poo to poo again and after a while they did and they both had normal poo after that!
But to be sure I still observed my chicks for few hours to notice anything strange in behaviour or any other symptoms showing.
So far all they've done is eat, drink, sleep, chirp around (and the occassional attempt to escape) all the chicks seem to be normal but I still can't discard the face I found redness in their poop :(

What should I do to determine for sure if its cocci or not? I don't want to just sit here thinking they're alright when in reality they might die soon :(

The chicks I have are 4 lavender brahma bantams 1 poland and 1 pekin bantam.

They have been in the brooder ever since they came which was at 3 days old, thank you so much I was worried sick :)