https://en.wikipedia.org/wiki/Coprophagia

Lagomorphs (rabbits, hares, pikas) and some other mammals ferment fiber in their cecums, which is then expelled as cecotropes and eaten from the anus, a process called "cecotrophy". Then their food is processed through the gastrointestinal tract a second time, which allows them to absorb more nutrition. While cecotropes are expelled from the anus, they are not feces and thus eating them is not called coprophagia.

Not technically poop, so the cereal should be totally safe to eat