Differential Diagnosis for Episodic Abdominal Colic with Vomiting in Adolescents

Primary Differential Considerations

The American Gastroenterological Association suggests that cyclic vomiting syndrome (CVS) and cannabinoid hyperemesis syndrome (CHS) are critical diagnoses to consider in adolescents with episodic abdominal colic and vomiting, with CHS being particularly important given the age group and rising prevalence of cannabis use among adolescents 1, 2
CHS should be suspected in any adolescent with chronic nausea and episodic vomiting, especially with cannabis use, with a mean age of CHS patients being 30 years, but 69% are male, making this diagnosis highly relevant for a 15-year-old boy 1
Key diagnostic features of CHS include stereotypical episodic vomiting resembling CVS with frequency ≥3 times annually, cannabis use >1 year before symptom onset, with frequency >4 times per week on average, and compulsive hot-water bathing behavior (reported in 71% of cases) 1
Resolution of CHS symptoms requires cannabis cessation for at least 6 months or duration equal to 3 typical vomiting cycles 1
CVS presents with stereotypical episodes of intense nausea and vomiting lasting hours to days, separated by symptom-free intervals, with four distinct phases characterizing CVS: prodromal, emetic, recovery, and interepisodic phases 1, 2
Cannabis use in CVS patients is typically occasional and often postdates the onset of episodic vomiting (making cannabis non-causal) 2

The key distinction between CHS and CVS is cannabis use pattern and temporal relationship, with CHS being preceded by prolonged (>1 year) and heavy cannabis use (>4 times weekly, often daily), and CVS having more occasional cannabis use that often postdates the onset of episodic vomiting 1, 2

Metabolic or endocrine causes, such as Addison's disease, hypothyroidism, and hepatic porphyria, can mimic CVS and should be considered, with testing dictated by individual patient history 2
Functional chronic nausea and vomiting syndrome should be considered after exclusion of structural abnormalities, with gastroparesis being less common in CVS patients, and gastric emptying scans not being ordered routinely 1, 2

Do not dismiss episodic vomiting in adolescents without thoroughly assessing cannabis use patterns, as many patients with CHS remain uncertain about the role of cannabis and attribute symptoms to food, alcohol, stress, or existing GI disorders 1
Avoid repeated esophagogastroduodenoscopy or upper GI imaging studies, as they may show epiphenomena of recent vomiting (mild gastritis, Mallory-Weiss tear, esophagitis) that are not causal 2
Do not order gastric emptying scans routinely, as few CVS patients have delayed emptying, and results during an episode are uninterpretable, with cannabis or opiate use complicating interpretation 2

A detailed cannabis use history, including duration, frequency, temporal relationship to symptom onset, and hot-water bathing behavior, is essential for diagnosing CHS 1
A basic laboratory workup, including CBC, electrolytes, glucose, liver function, lipase, and urinalysis, should be performed 2
A one-time upper endoscopy to exclude obstructive lesions, and selective testing based on clinical features, such as brain imaging, endocrine workup, or upper GI series, may be necessary 2, 3
A therapeutic trial of cannabis cessation for 6 months or 3 typical cycle lengths may be considered if CHS is suspected 1