Hi- I don t know if these two things are related but a few days ago I woke up with a very sore back- it felt like the lower back of my ribs had been hit with a bat from the inside out. I assumed I had slept funny, and it has gotten a bit better since then. However today, this is the third day in a row that my feces is coming out in somewhat normal shapes, however the individual logs are half brown (cappuccino colored) and half almost black (slightly darker than dark chocolate) There are distinct lines where the color changes but all on the same pieces. Almost like two pieces of different colored clay were pressed together? I haven t had any changes in my diet or exercise etc. is this normal poop what are things that could cause this?