Ooops, I forgot. Here's a link to the "poo page" that might help you figure out if there is anything abnormal going on.
http://www.chat.allotment.org.uk/index.php?topic=17568.0
How old is he? Bloody poo can be cocci and it does kill quickly if not treated, but it doesn't really sound like that is what is going on. If all you're feeding him is bread then the first thing you should do is get him on a better diet (flockraiser, gamebird feed, or even layer feed) because...