Differential Diagnoses for Recurrent Vomiting

Critical Initial Distinction

Bilious vomiting is a surgical emergency until proven otherwise, strongly suggesting obstruction distal to the ampulla of Vater, requiring urgent fluoroscopy upper GI series, as recommended by the American Gastroenterological Association 1, 2

Cyclic Vomiting Syndrome (CVS) affects approximately 2% of the US population, characterized by stereotypical episodes of acute-onset vomiting lasting <7 days, with at least 3 discrete episodes per year, and episodes separated by at least 1 week of baseline health, according to the American Gastroenterological Association 1, 3, 4
CVS is associated with prodromal symptoms, including impending sense of doom, panic, and inability to communicate, as well as constitutional symptoms such as fatigue, mental fog, anxiety, abdominal pain, and diaphoresis, as noted by the American Gastroenterological Association 1
Food Protein-Induced Enterocolitis Syndrome (FPIES) is particularly important in infants and young children, presenting with acute repetitive vomiting 1-4 hours after suspect food ingestion, without classic IgE-mediated allergic symptoms, as described by the American Academy of Allergy, Asthma, and Immunology 5
Gastroparesis is diagnosed by gastric emptying scintigraphy performed for at least 2-4 hours after radiolabeled solid meal, or by 13C breath testing, as recommended by the American Gastroenterological Association 2

Bilious vomiting requires immediate investigation, including fluoroscopy upper GI series, as recommended by the American College of Radiology 2

For suspected CVS, diagnosis is primarily clinical based on Rome IV criteria, with limited testing to exclude mimics, and early intervention during prodromal phase with sumatriptan combined with antiemetics (ondansetron), as recommended by the American Gastroenterological Association 1, 2, 3