What Does the Shape and Color of My Poop Mean?

Dear Lifehacker,
Like most people, I've pooped a lot in my lifetime. Usually things follow a fairly predictable pattern, but now and then I've seen unusual colors and shapes. I don't feel bad or have any discomfort, but I'm concerned these changes might mean something. How can I figure out when I should be concerned… » 3/04/14 5:48pm 3/04/14 5:48pm