belching
i ran across an article on the pathophysiology, diagnosis and treatment of excessive belching, which is a pretty common primary care issue, and i have mostly been treating it as a GERD symptom. but, of course, it is more complicated than that.... (see belching AJG 2014 in dropbox, or Am J Gastroenterol 2014; 109:1196–1203). it turns out that about 50% of the general population with dyspepsia report excessive belching. use of manometric testing/impedance monitoring has shown that there are 2 mechanisms: the "gastric belch", which is a vagally-mediated reflex with a relaxation of the LES (lower esophageal sphincter) and expulsion of gastric air, and a "supragastric belch" in which pharyngeal air is sucked into the esophagus when the diaphragm contracts and causes a negative intrathoracic pressure, then is quickly expelled before it reaches the stomach through relaxation of the UES (upper esophageal sphincter) and a closed glottis. a few commen...