Black Tongue

Expert Pediatrics Q&A

Many foods can turn your child's tongue different colors.
A lollipop or other food might discolor your child's tongue.. Photo by Tim Platt/Getty Images

Q. My son has had a stomach ache for a few days. It was mild and I wasn't too worried about it, but this morning he woke up with a black tongue. He otherwise seems fine, but I have never seen anything like it. What could be wrong with him? K. Benson

A. While there is a condition called black hairy tongue (lingua villosa nigra), which is caused by an overgrowth of bacteria or yeast on the tongue, most kids with a black tongue have a much simpler explanation...

Bismuth and Black Tongue

Did you give your child Pepto-Bismol recently?

Medications like Pepto-Bismol, or other drugs that have bismuth as an ingredient, can cause a black discoloration or staining on your tongue for a few days. It is harmless and goes away a few days after you stop taking the medication.

It occurs when bismuth combines with sulfur, which can sometimes be found in trace amounts in our saliva, forming bismuth sulfide. Since you can also have sulfur in your GI tract, taking medications with bismuth can sometimes also temporarily darken your stool.

Since your child had a stomach ache, it makes it even more likely that he could have taken some Pepto.

Interesting, many experts think that it is the bacteria in our mouth that are responsible for producing volatile sulfur compounds. And that sulfur is one of the things that can lead to bad breath. Once he is feeling better, it might be a good time to review his oral hygiene regimen and make sure he is brushing and flossing well and has been to the dentist recently.

Pepto and Reye Syndrome

Keep in mind that the main ingredient in Pepto-Bismol, bismuth sub salicylate, has been linked with Reye Syndrome, a potentially life-threatening disorder that has been associated with kids who take it and also have viral illnesses, especially the flu or chicken pox.

The Reye Syndrome association led the FDA to allow the original Pepto-Bismol and Kaopectate, which also contains bismuth sub-salicylate, to only include labeling instructions for children over age 12 years.

Some doctors go even further, though and recommend that even teens not take aspirin or salicylate-containing medicines. Since there are alternative medications, why take the risk?

Non-Bismuth Stomach Ache Remedies for Kids

There is a version of Pepto, the newer Children's Pepto Chewable Tablets that also help relieve 'heartburn, sour stomach, acid indigestion, and upset stomach due to these symptoms or overindulgence in food or drink.'

Instead of bismuth sub-salicylate, Children's Pepto Chewable Tablets only contains Calcium Carbonate as its active ingredient. So unlike the other forms of Pepto-Bismol, it would not be associated with Reye Syndrome and would be okay for younger children. In fact, Children's Pepto Chewable Tablets can be given to children as young as age two years old.

Also, Children's Pepto Chewable Tablets would not be expected to turn your child's tongue black...

Other Causes of Black Tongue

Now, if your child didn't take Pepto-Bismol or another medication with bismuth sub-salicylate that could have turned his tongue black, then you should likely see your pediatrician.

In addition to black hairy tongue, a child with a black tongue could possibly have:

  • a pigmented nevus of the tongue
  • drank or eaten something with a black dye or food coloring
  • drank or eaten something with a natural dye, like blackberries

Again, see your pediatrician if your child has a black tongue and hasn't taken a medicine with bismuth or if it doesn't quickly go away.


Körber, Andreas MD. Black hairy tongue in an infant. CMAJ. 2012 Jan 10; 184(1): 68.

Meyler's Side Effects of Drugs (Sixteenth Edition), 2016, Pages 990-994

Tarakji, Bassel. Diagnosis of oral pigmentations and malignant transformations. Singapore Dental Journal. Volume 35, December 2014, Pages 39–46

Continue Reading