I have a hen with bloody poo, just pooping blood it looks like on the roost. She had been acting depressed for about a week, sitting in one of the nest boxes nearly all day and pooping (regular looking poop) in it. This coincided with all the rest of the hens quitting laying. I have 18+ layers but have been getting 2-5 eggs a day(they are all different ages, most have already gone through the big molt). She happens to already be in an area where she is confined with 3 other layers and a rooster. Should I put something in their water to treat this? This particular group likes to poop in their water, too. It's always dirty even though I change it daily.