Introduction Gastric motor physiology can be assessed by gastric emptying scintigraphy (GES), 13C breath testing (GEBT) and real time gastric ultrasound (GUS). The aim of this study was to evaluate how commonly these tests are abnormal in patients with functional dyspepsia (FD).
Methods Twenty-seven patients fulfilling the Rome III criteria for FD were enrolled in the study. All patients had a normal upper GI endoscopy and underwent standard GES using 131I-technetium labelled mashed potato. On a separate day, these patients underwent a combined liquid GEBT (four hour breath test protocol using 170 ml chocolate Ensure liquid substrate + 50 mg 13C-acetate) and GUS (calculating antral area at the time of ingestion and 15 min after ingestion of the GEBT liquid test meal).
Results Eight of the 27 patients had one abnormal test, six had two and in five, all three tests were abnormal. In fifteen of the 27 patients with a normal GES (56%), eight had normal GEBT and GUS studies. Of the remaining seven patients, four had a normal GEBT and an abnormal GUS, two had normal GUS with an abnormal GEBT, and in one, both the GEBT and GUS were abnormal. GES was delayed in ten of the 27 patients (37%). In four of these, both GEBT and GUS were abnormal, three had delayed gastric emptying on GEBT with a normal GUS, two had delayed gastric emptying on GUS with normal GEBT, and in one patient, both GUS and GEBT were normal. GES was abnormally rapid in two patients (7%). In one patient, both GEBT and GUS indicated rapid gastric emptying and in the other, GUS revealed rapid gastric emptying with a normal GEBT. Assuming GES as the gold standard for diagnosing abnormal gastric emptying, GUS has a sensitivity and specificity for detecting a motor disorder of 66% and GEBT has a sensitivity of 66% and a specificity of 80%.
Conclusion In this group of FD patients, 70% had at least one abnormal test of gastric motor function. Whilst GES is regarded as the gold standard test, in seven patients with normal GES, the GEBT, GUS, or both, were abnormal. This discrepancy might reflect the day-to-day variability of gastric motor function testing or that each investigation measures a different component of gastric motor physiology. We conclude that in FD, adding GEBT and GUS to GES substantially increases the positive diagnostic yield and the heterogeneous patterns might indicate a variety of FD subtypes.
Disclosure of Interest None Declared.