My bunny has diarrhoea and im abit worried?

my little 10week bunny treacle has had diarrhea this afternoon. she has been out of hutch all day underneath it so i dont know if its dyration. she has drank alot of water since i put her back in hutch and ive gave her a little bath and cleaned her up. ive also took food away for now. we also have a 8week old guinea pig in the same hutch and i did put some carrot out for him. could it off been this and can i do anymore to help....???