No, it's typically not recommended1 to take Pepto Bismol while breastfeeding.
Here's the rundown: Pepto Bismol contains bismuth subsalicylate, and research has shown that salicylates can pass into breast milk. This might put your baby at risk of developing a rare but serious condition called Reye's syndrome2 , so the CDC recommends that breastfeeding parents avoid the use of bismuth subsalicylate compounds due to this risk.
That being said, if you're feeling under the weather and need some relief, it's always best to have a chat with your doctor. They're up to date with the latest studies and guidelines and can recommend a safe and effective treatment option for you. It's always better to play it safe when it comes to you and your baby's health.