Gastric belching and supragastric belching are two distinct pathophysiological
entities: A study using combined high-resolution manometry and impedance
monitoring
Boudewijn F. Kessing, Albert J. Bredenoord, André J.P.M. Smout
Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam,
Amsterdam, Netherlands.
Abstract
Background: Supragastric belches, but not gastric belches, are associated with severe belching
complaints. However, the exact mechanism of supragastric belching is not known. We aimed to
compare the esophageal pressure characteristics during supragastric belches and gastric belches
using combined high-resolution manometry and impedance monitoring.
Methods: We included 10 patients with complaints of severe and frequent belching. Combined
high-resolution manometry and impedance monitoring was performed during 90 minutes after a
standardized meal.
Results: Nine patients exhibited supragastric belches during the measurement. Eight out of nine
patients exhibited a specific pattern of supragastric belches which was characterized by concurrent
(i) movement of the diaphragm in aboral direction (median (IQR) displacement: 2 (1-2) cm) and
increase in median (IQR) EGJ pressure (20 (10-51) mmHg), (ii) pressure decrease in the esophagus
(5 cm: -10.7 (-13.2- -4.3), 10 cm: -9.3 (-12.4- -3.6), 15 cm: -7.7 (-8.3- -5.4) mmHg), (iii) upper
esophageal sphincter (UES) relaxation preceding the airflow, (iv) antegrade airflow and (v) increase
in esophageal pressure (5 cm: 17.7 (8.5-23.3), 10 cm: 13.2 (5.5-27.3), 15 cm: 20.6 (4.7-36.4)
mmHg) and air being forced out of the esophagus in retrograde direction. In contrast, gastric
belches were characterized by (i) decreased or unchanged EGJ pressure which was significantly
lower than during supragastric belches (0 (-2.5-0) mmHg, p<0.05), (ii) significantly higher
esophageal pressure or unchanged esophageal pressures, compared to supragastric belches,
preceding the esophageal airflow (5 cm: 2.5 (-0.6-5.7) (p<0.05), 10 cm: -2.3 (-12-2) (NS), 15 cm: 0 (4-2.3) (p<0.05) mmHg), (ii) retrograde airflow into the esophagus, (iii) common cavity
phenomenon characterized by an increase in esophageal pressure (5 cm: 16.3 (5.4-18.3), 10 cm:
14.0 (1.3-18.1), 15 cm: 18.0 (9.3-27.5) mmHg) which was not different from supragastric belches
and (iv) UES relaxation after the onset of the retrograde airflow. A specific phenomenon of
repetitive supragastric belches but not of repetitive gastric belches was observed in the majority of
patients. Notably, one out of nine patients exhibited a different pattern of supragastric belches in
which the antegrade airflow was preceded by an increase in pharyngeal pressure up to 250 mmHg
and not by a decrease in esophageal pressure.
Conclusions: Supragastric belches and gastric belches are characterized by two clearly distinct
esophageal pressure patterns. Movement of the diaphragm in aboral direction, negative
esophageal pressure and UES relaxation are essential events in the generation of a supragastric
belch.