When using these ingredients, your bowel movements will appear almost black, and so might your tongue. Of course, both will go back to their normal color when you stop taking the medicine. Also, do not take Kaopectate or Pepto-Bismol if you’re allergic to aspirin. Bismuth subsalicylate is related to aspirin, so you could develop an allergic reaction.
Another important point: do not give Kaopectate or Pepto-Bismol to children or teenagers who have a fever without first contacting your child’s doctor. They belong to a group of medicines called “salicylates.” Youngsters who receive aspirin or other salicylates during a viral infection may develop Reye’s syndrome. This is a serious and sometimes deadly condition in children that can harm the brain and liver. To be safe, doctors recommend that you avoid giving your children aspirin and other salicylates any time they have a fever or a viral infection. Also, ask your doctor or pharmacist before you take Kaopectate or Pepto-Bismol if you’re also taking a prescription medicine for diabetes, gout, arthritis, or to prevent blood clots. If you take these medicines together, you could have a serious side effect, like bleeding.