[Serious] Why defecation?

[John 6IX Breezy]

On the digestive system alone, no defecation. In other words, the entire biosystem could have been designed to make waste products unnecessary.

Boru

Right; perhaps I am being terribly unspecific. The definition of efficiency already includes the minimization of waste. So when I ask what improvement you would make, I'm asking how you would change our digestive system to achieve that. Saying that something isn't efficient doesn't mean much if you don't know how it can be improved.