Today In My BM I Found A Round Hard Substance

Today in my BM I found a round hard substance that was a pinkish color, also had blood in my stool. I removed the substance and tried to stick a pin in it, it was to hard to puncture so I got a razor blade and finally cut it open and on the inside was a sticky substance and around the outer edge was like bone fragment, also some on the inside of rock like substance. What is it? And should I be worried?