[Serious] Why defecation?

[BrianSoddingBoru4]

Similarly, if an animal consumes ten pounds of food and excretes one pound, that animal is not as efficient as it could be. Ideally, all ten pounds of food would go to producing energy. But some of that energy is used for excretion. 

I’m not claiming that digestive systems are NOT efficient. As far as they go, they appear to be sufficiently efficient. I’m pointing out that an omnipotent Creator could have made them perfectly efficient, and that it’s a legitimate question to ask, ‘Why not?’.

It seems to me that what you are trying to argue for is not that animals shouldn't deficate, but that whatever percentage of energy consumed isn't lost in feces.

For example, there is no metabolic need for cellulose fiber. So if you eat a pound of food which contains 50% fiber, letting 50% of that food pass through seems to me a reasonable option. Redesigning the entire system so that fiber is now metabolically demanded and not wasted, not only adds one more thing we can't live without, but also increases the metabolic demand of everything else that's needed to run whatever organ now uses fiber.

So rather than saying animals shouldn't deficate, you should see what percentage of energy consumed gets missed by digestion, let's say 10% of the sugar in an apple gets lost in feces, and argue that this should be minimize.

None of that matters. Give me a good and sufficient reason why God would design wombats to excrete 50% of what they eat when he could just as easily have designed them to metabolize 100% of what they eat.

Boru