The gastro-sphincteric pressure gradient: A new parameter to diagnose a rumination episode

Rumination is defined as the repetitive, effortless regurgitation of recently ingested food into the mouth. These episodes are preceded by a rise in intragastric pressure (IGP) and mainly occur postprandially. IGP peaks >30 mmHg have been proposed as a cutoff to differentiate rumination from reflux events. In clinical practice, we observed that this cutoff, which does not consider esophagogastric junction (EGJ) resistance, is not always reached.

We studied 27 patients with rumination syndrome [age: 43.6, 59% female] and 28 gastro-esophageal reflux disease patients [age: 45.9, 54% female]. For each rumination episode, reflux event, transient lower esophageal sphincter relaxation (TLESR), or straining without regurgitation, the following parameters were registered: maximal IGP, IGP, and EGJ pressure preceding the respective episodes. We also quantified the gastro-sphincteric pressure gradient (GSPG) prior to the respective episodes.

Five reflux episodes were characterized by a maximal IGP >30 mmHg. In 28% of the rumination episodes, the IGP peak did not exceed 30 mmHg. Median GSPG was positive for rumination episodes and significantly higher compared with TLESRs, reflux episodes, and straining without regurgitation (7 [3-13] vs. 0 [-1-0] vs. 0 [-1-0] vs. -9 [-13--2]; p < 0.0001).

Applying the proposed cutoff of 30 mmHg, 28% of the rumination episodes were missed. We found that the GSPG differentiates between rumination (positive GSPG), TLESRs and reflux events (GSPG around 0), and straining without regurgitation (negative GSPG). We propose a GSPG value ≥2 mmHg to distinguish rumination from reflux episodes, TLESRs, and straining without regurgitation.