I don't know why someone hasn't answered you. Sometimes if you eat like a tomato you can see the skin or part of it in a stool. I don't know what the black would be, usually that means dried blood.
Do you have any symptoms that could be tied to a bleeding ulcer or hemorrhoid? How much black and red do you see? If it is a lot you should tell your doctor so that they could test for blood in your stool to at least rule that out.
I have an external hemorrhoid that is driving me crazy from being on Prevacid now and previously Nexium and being constipated with those meds. I'm just using Preparation H right now. It's just minor but uncomfortable.
Hypothyroidism (1953), diabetes type 2 (1976), hypercholesterolemia (1989), gastroparesis (1990), FMS (1995), and GERD (2006).
FMS: Prozac, Xanax, Lortab.
Other meds: Prevacid, Cytomel, Detrol, Reglan, Novolog insulin, Novolin N insulin, Bumex, Lipitor.