In children an intragastric pressure rise >25 mmHg associated with retrograde bolus flow into the proximal oesophagus has been proposed as diagnostic cut-off for rumination episode, but this can still fail to diagnose rumination events¹. Gastro-sphincteric pressure gradient (GSPG), the difference between intragastric pressure (IGP) and oesophago-gastric junction (EGJ), is a new parameter for diagnosis of rumination syndrome during high resolution oesophageal impedance manometry (HRIM) in adults². A difference ≥2mmHg prior to retrograde oesophageal bolus flow is diagnostic. We aimed to evaluate its use in diagnosis of paediatric rumination.

Children with confirmed rumination syndrome who had a multichannel intraluminal pH-impedance monitoring (pH-MII) and HRIM between January 2015-December 2021 were identified. Diagnosis of rumination syndrome was based on HRIM conventional criteria with rise of IGP prior or during a retrograde bolus flow. All children with rumination syndrome had a normal pHMII study. An age and sex-matched gastroesophageal reflux disease (GERD) group was included. Children in the GERD group had pathological oesophageal acid exposure time (>6%) and negative HRIM for rumination syndrome. All episodes of rumination, reflux, straining without regurgitation and transient lower oesophageal sphincter relaxation (TLESR) were analysed to calculate the GSPG.

Thirty patients were included; 15 children with rumination syndrome (6 male; mean age 12.7±2.5 years) and 15 with GERD (7 male; mean age 12±2.9 years). No difference was found in lower oesophageal sphincter mean resting pressure between the two groups (26.1±11.1 vs 25.9±11.8; p=0.9). In total, 80 rumination episodes, 23 reflux events, 22 straining events without regurgitation and 14 TLESRs were detected. GSPG was significantly higher in rumination event compared to all other events (table 1). In 31 of the 80 rumination episodes IGP peak did not exceed 25 mmHg which occurred in 9 out of 15 children with rumination syndrome. Based on ROC analysis we found that a GSPG >1.5 mmHg can identify rumination episodes with sensitivity of 90% and specificity of 95% compared to IGP >25 mmHG which has 51% sensibility and 86% specificity (figure 1).

GSPG can be used to diagnose paediatric rumination syndrome and reliably differentiate rumination episodes from reflux events, abdominal straining without regurgitation and TLESRs.

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Abstract OC90 Figure 1

Predictive value of GSPG and IGP for rumination episodes

References

1. Singendonk MMJ, Oors JM, Bredenoord AJ, et al. Objectively diagnosing rumination syndrome in children using esophageal pH-impedance and manometry. Neurogastroenterol Motil. 2017;29(5).

2. Geysen H, Michielsen S, Rommel N, et al. The gastro-sphincteric pressure gradient: a new parameter to diagnose a rumination episode. Neurogastroenterol Mot. 2021;33(6):e14068.