Can Pepto Bismol or Kaopectate Turn Your Stool Black?

Question: Can Pepto Bismol or Kaopectate Turn Your Stool Black?

Answer: Yes. Taking Pepto Bismol or Kaopectate can turn your stool a dark color, sometimes green or even black. This is caused by the active ingredient -- bismuth subsalicylate.

The black or green stool can last for several days, but it is harmless. This change in stool color is not a cause for concern unless you have stopped taking the bismuth subsalicylate and the unusual stool color persists.

_Sources:

^{American Society of Health-System Pharmacists, Inc. "Bismuth Subsalicylate." MedlinePlus. 01 June 2007. 23 Oct 2008.}