Background: Rumination is an eating disorder clinically suspected in the presence of chronic regurgitation of recently ingested food with subsequent re-mastication and swallowing. Oesophageal manometry is currently used to confirm the diagnosis, however, it is difficult to distinguish rumination from postprandial belching-regurgitation, being the manometric pattern identical in both situations. Oesophageal impedance allows recognition between liquid and gas gastro-oesophageal reflux. Our aims were (i) to improve diagnosis of rumination using combined impedance-manometry (ii) to assess the gastro-oesophageal pressure-flow pattern in rumination events.
Methods: Sixteen patients with clinically suspected rumination underwent impedance-manometry monitoring for 1 h after a solid liquid meal. Manometry was first analysed blindly to the impedance pattern. All events marked by the patients and straining episodes were identified. After the manometric analysis, impedance tracings were unblinded and each straining episode was analysed for presence of liquid and/or gas oesophageal retrograde flow. Only rumination events were included for additional evaluation.
Key results: Postprandial manometry showed a pattern compatible with rumination in 12/16 patients. In total, impedance-manometry confirmed the clinical diagnosis of rumination in eight of the 16 patients with clinical suspicion of rumination. In 102 clearly identified rumination events, the onset of gastric strain (manometry) occurred before the onset of oesophageal liquid retroflow (impedance) in 58% of cases or simultaneously in 37% of cases. In most cases (86%), oesophageal retrograde flow started after an initial increase in abdominal pressure but before the peak gastric strain pressure.
Conclusions & inferences: Postprandial impedance-manometry monitoring improves diagnosis of rumination because it allows distinction between rumination and postprandial belching and regurgitation. During rumination, oesophageal liquid retrograde flow is first driven by an early small rise in intragastric pressure preceding the peak pressure observed during straining.