Fecal matter is usually large intestine. It’s chyme in the small intestine. Some of the defining characteristics of fecal matter are things like the large amount of bacteria (up to 1/3 of its weight at exit), the color (yay bilirubin conversion), and the compaction (and simultaneously occurring dehydration). When we’re missing those things, we usually identify it as something other than feces. That means, nominally, that you don’t really have much poop until you’re well into the large intestine. Color is the weakest of those, but it is such a good indication of something going wrong if changed that I would say it is a part of anything that could be considered ‘true poop.’