Not sute but i think that bacterial infection listed above is what they get from bad feed..... dark blackish diarrhea sometimes, or watery...the dead givaway is undigested grains in it. It mostly is water with bits in it. I am pretty sure the roo i lost last year to persistant diarrhea had this (learned of it after. Of course) duramycin did NOT help and may have worsened it...for the rest of yhe flock i switced feed companies and started giving anything with probiotics!!!