Ok, lets try to figure this out. As far as the crops go I think there is a good chance they just stuffed their little piggy/chickie faces. You can check for that by taking their food away for the night and checking them first thing in the morning. If their crops are back down in the a.m. then everything is fine there. If not then you'll need to start with the olive oil.
As far as the blood in the poo that sounds like cocci. First thing in the morning you're going to want to call around to your local feed stores and find some Corid or Sulmet. I like Corid better because I don't think it's as hard on them. Cocci can kill them pretty quickly, BUT they usually respond well to treatment so hopefully you'll be fine. I'd really like to see some more pictures of the bloody poo though, because the one you posted didn't really look that bloody (which is a good thing) so it might not even be cocci. I'd still try to get the Corid though because it's good to keep on hand.