Symptoms that can be attributed to the gastroduodenal area are classified into five categories: (1) Functional Dyspepsia, with two subcategories that can overlap: Postprandial Distress Syndrome, with meal-induced symptoms of postprandial fullness or early satiation and Epigastric Pain Syndrome, with epigastric pain or burning that does not occur exclusively postprandially; (2) Nausea and Vomiting Disorders, which include three subcategories: chronic nausea and vomiting syndrome; cyclic vomiting syndrome; and cannabinoid hyperemesis syndrome; (3) Excessive Belching Disorders, defined as audible escapes of air from the esophagus or the stomach and classified into 2 subcategories depending on the origin of the refluxed gas: gastric or supragastric belching; (4) Inability to Belch Syndrome, a new category defined by the self-reported inability to belch; and (5) rumination syndrome, defined by the repetitive, effortless regurgitation of recently ingested food into the mouth followed by the reswallowing or expulsion of the food bolus.
Tornblom et al. (Sun,) studied this question.