Black is from bleeding...blood that's from internal bleeding is black, like coal. If you smeared some on white paper, it is actually black not brown. They do sell Hemoccult kits at the drug stores, just put a small sample on the card...and turn it over and apply the solution. The color changes show if the dark color in the stool is indeed blood or not. If you don't feel comfortable or confident in testing it yourself...take a sample to your vet, yep, put it in a baggie...they will test it for you. Is his poop solid or runny? Does he seem to go more often and urgently? If so yes, by all means get him back to the vet ASAP. When they are bleeding from the rectum...they can not hold it...it just comes out, seeps. I certainly hope and pray he's not bleeding...when did you first notice the color change? Was it after he ate anything that may have color in it?
__________________ As Ever, Kathy 
Intruducing Bentley  Winston and Spencer: RIP My Sweet Angels |