Easily digestible food is processed in the gastrointestinal tract and expelled as regular feces. To get nutrients out of hard to digest fiber, rabbits ferment fiber in the cecum (part of the gastrointestinal tract) and then expel the contents as cecotropes, which are reingested (cecotrophy or refection). The cecotropes are then absorbed in the small intestine to use the nutrients. Soft cecotropes are usually consumed during periods of rest in underground burrows.
I think OP is implying we should eat shit.
That’s basically what rabbits do. From Wikipedia:
Humans may be unique among mammals for not eating our own shit, the shit of others, or just any random shit we find.
That’s not my experience during my college years.