After usisng peptal bismal my stool turn black what can i do to get back to normal color

Hello. Thank you for writing.

This discoloration is temporary and harmless. 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. It will go away on its own.

Helena