Wow, after reading some of the other posts in this forum I feel very unknowing about chickens. I thought I knew at least a little. My husband and are new to all of this for sure. We have a total of four chickens. Our first two are 20 week old leghorns that we got from my mother-in-law. She has had them since they were hatched. We got them five weeks ago. Two weeks later we got a one-year old sexlink that was already laying and has been laying about every other day until it hit 100 degrees last week. About 4 days ago we got a year and a half old RIR. She is supposed to be laying but we havent seen an egg yet. And, before anyone says this all important note, I will say it myself since it has become oh-so obvious to me now (hindsight is 20-20 as they say)-Always quarantine!!! I dont actually know if we have a disease or not and that is why I am writing this. Here is my problem, the sexlink seemed to be fine. When I opened up the coop to let them out this a.m. I noticed that there was bloody stool in the coop. I wasnt sure which one it was coming from so I watched them for a bit. The sexlink has bloody diarrhea. It is quite watery. Neither her backside or any of the other girls is dirty from what I can tell. I have read several other posts and was hoping to get the specific symptoms of Mareks and some of the other problems but havent come upon the right post yet I guess. Can anyone tell me what is wrong with her and maybe what we should for her? If you need any more information I would be happy to provide it if I can. Thanks for your help, I look forward to seeing what you all have to say.