A New Side Effect of Cannabis: Doctors Stop Thinking

Jordan Tishler MD

Written by
June 16, 2026

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A New Side Effect of Cannabis: Doctors Stop Thinking

Clinicians are seeing more patients who use cannabis.  Some patients use it for medical purposes like insomnia, chronic pain, or anxiety. Others use it purely for enjoyment. 

Nonetheless, we’re seeing that as use increases, so does a troubling diagnostic reflex: when a patient reports cannabis use along with nonspecific gastrointestinal symptoms, cannabis hyperemesis syndrome (CHS) too often becomes the default conclusion.

I recently received a message from a patient whose physician reached this conclusion immediately after learning she used cannabis. Despite lacking hallmark symptoms, she was given no further evaluation. The encounter left her anxious and without an actual diagnosis—a story many physicians should take to heart.

CHS Is Rare

Despite its increasing mention in emergency departments, CHS is uncommon.

A review of emergency and inpatient data suggests an incidence of less than 6% among frequent cannabis users presenting with vomiting, and fewer than 3 per 1,000 regular users in population-level studies [Sorensen et al., Annals of Emergency Medicine, 2020].

Given that more than 16 million adults in the U.S. report regular cannabis use [SAMHSA, 2024], most users will never experience CHS.

CHS Is Not a Mild Condition

True CHS is usually severe, often requiring IV fluid resuscitation and antiemetic therapy.

Diagnostic case series describe multiple hospitalizations with recurrent, intractable vomiting lasting days, significant hypokalemia, and weight loss exceeding 5–10% of body weight [Allen et al., Gut, 2004; Simonetto et al., Mayo Clin Proc, 2012].

Milder presentations are far more likely attributable to other causes—functional dyspepsia, biliary disease, gastritis, or medication effects.

CHS Is a Diagnosis of Exclusion

By definition, CHS requires ruling out other anatomic, metabolic, and infectious etiologies. Rome IV requires presentation of stereotypical episodic vomiting, prolonged cannabis use, and symptom relief with sustained cessation; therefore, cannabis exposure alone is not diagnostic.

The Rome IV criteria emphasize exclusion of alternative gastrointestinal, hepatic, and endocrine disorders before attributing vomiting to cannabis use [Rome Foundation, 2016]. Premature attribution risks significant diagnostic error, especially with overlapping presentations like gastroparesis or cyclic vomiting unrelated to cannabis.

A Clinically Guided and Diagnostically Appropriate Workup Is Essential

Responsible evaluation should include, or at least consider whether appropriate:

  • Labs: CBC and comprehensive metabolic panel (including electrolytes and LFTs). Unless recently done, HgA1c would be useful to rule out occult diabetes presenting as gastroparesis.
  • Imaging: Abdominal I+ CT or ultrasound when symptoms suggest biliary or structural pathology.
  • Endoscopy: EGD to assess mucosal and upper GI disease when persistent or severe symptoms occur.  Gastric emptying study would be important as well.

Cannabinoid hyperemesis syndrome is increasingly invoked whenever a patient who uses cannabis presents with nausea, vomiting, or abdominal pain. Absent these assessments, assigning CHS is speculative and potentially negligent.

Avoiding the assumption that cannabis exposure leads to CHS leads to better patient outcomes.

Why It Matters

CHS exists, and we must recognize it when present. But any diagnosis of exclusion requires adequate clinical thinking and laboratory study.  Anything less will lead to an incorrect diagnosis which is a harm to the patient.

Furthermore, casual diagnosis based on cannabis history alone erodes patient trust and undermines the credibility of evidence-based care. As cannabis becomes a normalized therapy, physician responsibility is not to stereotype, but to scrutinize—with data, not assumptions.

Thoughtful diagnosis still matters. Let’s practice it the same way in cannabinoid medicine as we do everywhere else.

References:

  1. Simonetto DA, Oxentenko AS, Herman ML, Szostek JH. Cannabinoid hyperemesis: a case series of 98 patients.Mayo Clin Proc. 2012;87(2):114-119. PMID: 22305024.  https://pmc.ncbi.nlm.nih.gov/articles/PMC11597608/
  2. Rome Foundation. Rome IV Criteria: Cannabinoid Hyperemesis Syndrome (CHS). Diagnostic criteria require stereotypical episodic vomiting, prolonged cannabis use, and relief with sustained https://theromefoundation.org/rome-iv/rome-iv-criteria/
  3. Sorensen CJ, DeSanto K, Borgelt L, Phillips KT, Monte AA. Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment—a Systematic Review. J Med Toxicol. 2017;13(1):71-87.  https://pubmed.ncbi.nlm.nih.gov/28000146/
  4. Allen JH, de Moore GM, Heddle R, Twartz JC. Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse. Gut. 2004;53(11):1566-1570.  https://pmc.ncbi.nlm.nih.gov/articles/PMC1774264/
  5. Senderovich H, Patel P, Jimenez Lopez B, Waicus S. A Systematic Review on Cannabis Hyperemesis Syndrome and Its Management Options. Med Princ Pract. 2022;31(1):29-38. doi: 10.1159/000520417. Epub 2021 Nov 1. PMID: 34724666; PMCID: PMC8995641. https://pmc.ncbi.nlm.nih.gov/articles/PMC8995641/