Pipe Poop

So, I went to replace the kitchen sink faucet today, and discovered the pipes under the sink were not securely attacked to each other. It is a double sink, and one of the elbows from the down pipe came off (Pardon me for my DIY terminology) then the other. The second one, then came loose from the trap. And I saw, what I first thought, was something that would connect them. But, upon further examination, it was crud that had accumulated over the years. Now, I have no idea exactly how many. Probably at least 23, (when the building was purchased by my wife's family) maybe over 100. As I tried to get the clump out of that end, I realized the pipe was full. I gently took apart another connection of that line, and got the stuff out. It has the shape, smell and texture of poop. I know, because I have a dog. Although it was wider than any poop I'd seen before. Not that I've been to the Poop Museum, or have every googled, "Poop" or any other form of that word. Funny thing, the other pipe before the trap was perfectly clear. I guess it had it's fiber.