Objective manometric criteria for the rumination syndrome

The rumination syndrome is a behavioral disorder resulting in recurrent regurgitation of undigested food. The diagnosis of this syndrome is currently based on clinical features. We aimed to determine criteria for the rumination syndrome based on physiological measurements. We studied patients with clinically confirmed rumination syndrome and gastroesophageal reflux disease (GERD) patients with predominant symptoms of regurgitation. All patients underwent combined high-resolution manometry and pH-impedance measurement after a standardized meal. All reflux events extending to the proximal esophagus were analyzed. Furthermore, ambulatory measurements were performed in the majority of patients. In the rumination group, the amplitude of the abdominal pressure increase during proximal reflux events and the esophageal pressure peaks were significantly higher compared with GERD patients. None of the GERD patients exhibited abdominal pressure peaks >30 mm Hg, whereas in the rumination patients 70% of the pressure peaks had an amplitude >30 mm Hg. Abdominal pressure patterns were also observed during ambulatory pH impedance-pressure monitoring in the rumination patients. pH-impedance monitoring alone could not differentiate between GERD and rumination, however, a higher percentage of reflux events reached the proximal esophagus in the rumination patients. Notably, three different mechanisms of rumination were observed: (i) primary rumination, in which the abdominal pressure increase preceded the retrograde flow, (ii) secondary rumination, consisting of an increase in abdominal pressure following the onset of a reflux event and (iii) supragastric belch-associated rumination, consisting of a supragastric belch immediately followed by a rumination event. The diagnosis of the rumination syndrome can be made when reflux events extending to the proximal esophagus that are closely associated with an abdominal pressure increase >30 mm Hg and an esophageal pressure increase are observed during combined pressure-impedance monitoring