Diagnostic Approach and Imaging for Vomiting

Initial Assessment and Diagnostic Imaging

The initial diagnostic approach for a patient presenting with vomiting should begin with determining whether the vomiting is bilious or non-bilious, as bilious vomiting strongly suggests obstruction distal to the ampulla of Vater and requires urgent evaluation with fluoroscopy upper GI series, according to the American College of Radiology 1
Fluoroscopy upper GI series is the most appropriate initial imaging study to rule out malrotation with volvulus or other obstructive causes in patients with bilious vomiting, as recommended by the American College of Radiology 2, 1

In patients with suspected gastroesophageal reflux, fluoroscopy upper GI series may be appropriate as initial imaging, according to the American College of Radiology 2
In patients with suspected gastroparesis, gastric emptying scintigraphy of a radiolabeled solid meal is the best accepted method, with the test ideally performed for at least 2-4 hours after meal ingestion, as stated by the Gastroenterology society 3
In patients with suspected cyclic vomiting syndrome, diagnosis is primarily clinical based on Rome IV criteria, with imaging used to exclude other causes, according to the Gastroenterology society 4, 5

In patients with suspected gastroparesis, breath testing using non-radioactive 13C isotope can be an alternative to scintigraphy, as stated by the Gastroenterology society 3
For cyclic vomiting syndrome, early intervention during the prodromal phase with abortive therapies (sumatriptan combined with antiemetics like ondansetron) is critical, according to the Gastroenterology society 4
For emergency department management of severe vomiting, IV fluids, antiemetics, and in cases with severe pain, non-narcotic analgesics like IV ketorolac as first-line, as recommended by the Gastroenterology society 4
For gastroparesis, treatment should target the underlying cause when possible, with prokinetic agents often used, according to the Gastroenterology society 3

Failing to recognize bilious vomiting as a potential surgical emergency, especially in neonates where it may represent midgut volvulus in 20% of cases, as noted by the American College of Radiology 1
Performing inadequate duration gastric emptying studies (less than 2 hours), which may miss cases of gastroparesis, as stated by the Gastroenterology society 3