I have a lot of severe, execruating stomach pain. My tounge is turning black and it feels really slick, I brush it to no avail, It comes back. I had my doctor to look at it and he did from the other side of the room.He commented you need to brush your tongue. said it looked fine but it is not fine. when these attacks happen I feel as if I am dying.Doctor put me on sulfer drugs, that are not working and deemed it to be a bacterial infection. need to know what to do about it. And what is it?.