Its possible they took pepto bismal the night before. If you look on the bottle it is a side effect. Happened to me one time and I totally flipped out. I traced back what I had done the night before and I had eaten two pepto bismal tablets and it clearly lists on the box that a black tongue is a major side effect. I brushed my teeth and tongue several times and was able to get most of it off.

Oh my gosh..Thats insaine!! Does she smoke? The only time I have heard of that is with mouth cancer.

~sara~

I had an upset stomach last night and took some pepto bismol tablets before bedtime and woke up with a black tongue. I surfed for some answers and was pleased to find the response posted here, thanks. My only question now is why does pepto cause a black tongue, pretty gross side effect.

Whew....I am living in a remote corner of china and I awoke to find my tongue was completely black. Before making the long trek into a town to seek medical attention I found this website. I took pepto bismal last night, and I am relieved...I am still going to a doctor........But I am relieved.