Symptoms that can be attributed to the gastroduodenal region represent one of the main subgroups among functional gastrointestinal disorders. A slightly modified classification into the following 4 categories is proposed: (1) functional dyspepsia, characterized by 1 or more of the following: postprandial fullness, early satiation, epigastric pain, and epigastric burning, which are unexplained after a routine clinical evaluation; and includes 2 subcategories: postprandial distress syndrome that is characterized by meal-induced dyspeptic symptoms and epigastric pain syndrome that does not occur exclusively postprandially; the 2 subgroups can overlap; (2) belching disorders, defined as audible escapes of air from the esophagus or the stomach, are classified into 2 subcategories, depending on the origin of the refluxed gas as detected by intraluminal impedance measurement belching: gastric and supragastric belch; (3) nausea and vomiting disorders, which include 3 subcategories: chronic nausea and vomiting syndrome; cyclic vomiting syndrome; and cannabinoid hyperemesis syndrome; and (4) rumination syndrome.