why does pepto-bismal go down pink, and come out black?

Answer 1

I have also awaken to a black tongue! It has a metallic taste too. I noticed the tablets are more likely to cause it than the liquid, for me anyway.

This is what I found on the site in my source(s):
I noticed that Pepto-Bismol sometimes darkens the tongue/stool. Why does this happen and how long does it last?
The active ingredient in Pepto-Bismol contains bismuth. When a small amount of bismuth combines with trace amounts of sulfur in your saliva and gastrointestinal tract, a black-colored substance (bismuth sulfide) is formed. This discoloration is temporary and harmless. It can last several days after you stop taking Pepto-Bismol. Individual bowel habits, your age (the intestinal tract slows down with age), and the amount of the product taken all help to determine how long Pepto-Bismol is in your system.

Answer 2

I've taken it and moments later puked it back up and it was still pink !

Answer 3

it actually says something about that on the bottle or box.
Once i took it and woke up with a black tongue and thought I was hemorrhaging and the black on my tongue was actually dried blood!! Scared me to death!