The question “Did poop smell before the ‘Fall’?” is answered from several theological perspectives at the blog Preach It, Teach It. I quote the part of the answer I thought was funny, emphasis mine.
If you are a seven-day, twenty-four-hour creationist then you have to decide whether or not the animals … ate and pooped before Adam and Eve had time to eat the forbidden fruit? If they did poop before the Fall, then poop did not smell because decay did not occur until after the Fall. But, then on the other hand, you have to consider the fact that poop by its very nature is decay. If the first poop came after the Fall then, of course, poop stank. Poop continues to smell as a residual reminder of the Fall into sin.
One need not be a 7/24 creationist to derive logical conclusions from a set of premises; whether or not those premises are right or wrong is a different issue. So given the premise “No decay before the Fall” and the notion that what’s going on inside poop is decay, we are led to conclude that poop wouldn’t stink. Wouldn’t, that is, if what’s going on in poop is indeed decay. The remaining hurdle is to support the proposition that the biologic processes of bacteria and fungus breaking down organic matter is properly classified as “decay” of the sort that arrived with the curse. I’m pretty confident that it’s not.
I would think that Curse-worthy decay would destroy and consume and ruin. What happens to poop via the stink-making bacteria-and-fungus process isn’t waste and ruin but reprocessing. Reuse! You wouldn’t heap ruin onto your garden, would you? Poop isn’t ruin, it’s useful stuff.
Perhaps we can get away with calling human death a part of the curse, but nature’s reclaiming of the corpse to put the now-dead body’s materials back to good use isn’t a broken, cursed system, is it? I would imagine that any curse would be interested in breaking this miraculous process of reuse. Nature’s reclaiming of God’s materials to use again as part of God’s creation seems like a brilliantly functioning plan, not a curse.