sometimes its hard to figure out what they have gotten into....usually i just keep my eye on things but i find all kinds of things when i am either picking up poop after them while on a walk or in the yard...little peoples heads(fisher price toy) lol, stick pieces, plastic, you name it i am always after my two not to eat stuff but they always seem to find something the only toy they can have now are the nylabones.(they are not allowed to eat the kids toys but sneak them) and yes anything with food colouring will change the colour of their poop maybe even from the food change who knows...i hope it goes away and things are okay....