I have been having a digestive problem for several months now, and I just wanted to get some advice on what this could be. For the past few months I have had something that looks like dust coming off of my BM and an odd metalic with acid smell coming from it. It's color has been a brown mixed with yellow, white, orange, and black. I know it's not mixed with blood the black color came from diet, what could be come of the causes of this? I have also had a lot of mucus coming out with it as well I don't know why though.