the most common side effect with taking too much pepto-bismol is the temporary and harmless black darkening of the tongue and stools. this can subside and is caused by a reaction to sulfa in the mouth. however there are more serious side effects with toxic levels of pepto-bismol such as severe allergic reactions (rash hive itching difficulty breathing tightness in chest swelling of the mouth face lips or tongue) fever hearing loss nausea ringing in the ears severe constipation and vomiting. if any of these symptoms do occur stop taking the medication and consult your health care professional.
are there side effects from taking too much pepto-bismol?