Originally Posted by
Spanky
It is always helpful though gross, to post pictures of the poop since it speaks volumes of info.
Is the poop still "Pale and Mushy"? That is typical of over-feeding, but that dose not sound like the issue here.
It sounds like the blood in the poop is pink or red )"fresh blood" and not tarry and black (old blood)... did you examine her bottom for signs of a scratch or other injury? If she is with other litter mates, they can end up with small scratches from crawling on one another.
What is the amount of blood? If it is a a lot, giving some vitamin K-1 may help.
Best case it is GI upset from the formula switching that will resolve itself with time.