Introduction Inability to burp or belch occurs when the upper esophageal sphincter (cricopharyngeus muscle) cannot relax in order to release the “bubble” of air. The sphincter is a muscular valve that encircles the upper end of the esophagus just below the lower end of the throat passage. If looking from the front at a person’s neck, it is just below the “Adam’s / Eve’s apple,” directly behind the cricoid cartilage. If you care to see this on a model, look at the photos below.
