Poss sick hen

[Irishmom80]

Not sure but I think that I have a hen with coccidiosis. I was told that corrid is medicine to treat them with. They all seem to be okay, but I've got a boy going through puberty that won't leave one girl alone. I have lost one recently and I thought it was him picking on her but now I don't know. I've read that stress can cause runny stools, or the coccidiosis is the culprit. They get red pepper flakes in their feed along with oregano. And what do I do about the young man that doesn't know that no means no. Is there anything I can do to deter him?