Why does poop smell ?
Well… you see… poop smells bad because the good bacteria, called Gut flora, that aids our digestive process also creates bad smelling byproducts that actually contain sulfur. According to the eNotes/Wikipedia page on the subject (and yes eNotes does have a page on this subject), the names of these stinky aromatic organic compounds are indole, skatole, and thiols. The bacteria also produce hydrogen sulfide gas as a byproduct, which is also responsible for making our gas smell bad.
The Skatole compound is actually only stinky when it is in high concentrations. It is the same compound that in lower concentrations makes certain flowers smell good. It is even used in many perfume fragrances. But you will excuse me if I don’t want to think about this the next time I dab some perfume behind my ears.
Mostly due to the foods and drinks injested. But also combined with bacteria in the body, which creates a sort of sulfur smell. So combine that with the result of the portion of food that is not absorbed by the body and there you have it. Obviously, if you eat a lot of processed foods or food and drink with dies and preservatives will create smellier fecies that if you're eating vegetables and organic foods.