I have 9 month old RIRs. Earlier this week I noticed one that had poop stuck to her bottom. Yesterday she looked like she wasn't feeling well, and seemed to be having trouble passing stool. I spent some time looking online, and went out today to examine her. I was checking to see if she had a prolapse, but what I found instead was a walnut sized hard ball of poop. I pushed around her vent, and it popped out. I have separated her from the rest of my flock, and I am trying to keep her as still as possible until she perks up. What might cause this, and am I doing all that I need to do? Any help would be greatly appreciated!