One of my Rhode Island Red who is about 4 years old stopped laying a few weeks ago and started sleeping in the nesting box instead of the roost. Ok, not that serious. About a week later I noticed she has this dark blue/black diarrhea (does not appear to have worms in it). She is now sleeping on the floor at night in the coop and tonight was having difficulty getting into the coop and I had to pick her up and put her in. Her feet look ok and she seems to be walking normally. Her comb is pale and drooping to the side a bit since the start of all of this. I did try treating with Corid but no signs of improvement. She is eating and drinking. Seems to be a bit tired at times when I see her out in the yard she will stay in one spot for a little bit and rest. Any input would be greatly appreciated. Thank you