When CHS Looks Like a Surgical Complication: A Case Report That Every Perioperative Team Needs to Read
A newly published case report in Cureus documents a situation clinicians are increasingly likely to encounter but rarely prepared for: a patient whose cannabinoid hyperemesis syndrome went unrecognized after surgery because her symptoms were indistinguishable — at first glance — from routine postoperative complications.
The report, authored by Justin B. Atkins, Daniel Levine, and Laura Shaw and published on July 15, 2025 (DOI: 10.7759/cureus.87990), shines a light on a blind spot in perioperative medicine. While CHS has gained recognition in emergency departments over the past decade, it remains poorly understood — and frequently missed — in surgical settings, where the overlap with common postoperative phenomena creates a dangerous diagnostic fog.
The case: vomiting that wouldn’t stop after surgery
The patient was a woman who underwent a gynecological procedure that included placement of a mid-urethral sling. From the first day after surgery, she experienced persistent nausea and vomiting. The clinical team’s initial working assumption was that the symptoms were attributable to the effects of anesthesia, opioid-induced nausea, or possible surgical complications — all plausible explanations in the immediate postoperative period.
Abdominal examination was reassuring: soft, non-distended, with normal bowel sounds and no tenderness. No imaging was ordered. Standard antiemetics were administered — ondansetron 4mg IV every eight hours and metoclopramide 10mg IV every eight hours — but by postoperative day two, the patient had experienced three additional discrete vomiting episodes despite this treatment.
At that point, her care team revisited her substance use history more thoroughly. This time, the patient disclosed something she had not volunteered initially: she had been using cannabis daily for approximately two years, consuming roughly one gram of cannabis flower per day purchased from a licensed dispensary — a product with significant THC concentration.
Armed with this new information, the team recognized the clinical picture: chronic cannabis use, cyclical vomiting refractory to standard antiemetics, and symptom resolution with supportive care and cannabis abstinence. The diagnosis was cannabinoid hyperemesis syndrome.
By postoperative day four, her condition had turned around substantially. She progressed from ice chips to soft foods, remained free of nausea and vomiting for over 12 hours, and was cleared for discharge with normal electrolytes and thorough counseling on CHS — including a clear recommendation to stop using cannabis entirely.
Why CHS is so easy to miss after surgery
The authors explain the mechanism behind CHS through the lens of CB1 receptor biology. Chronic, heavy THC exposure leads to progressive overstimulation and eventual downregulation of CB1 receptors in both the gastrointestinal tract and the hypothalamus. The result is impaired gastric motility and a dysregulated emetic reflex. Functional MRI research has confirmed that sustained THC exposure alters cannabinoid signaling along both central and enteric pathways — ultimately producing the paradox of hyperemesis in someone using a substance widely known for its antiemetic properties.
That paradox is precisely what makes diagnosis so difficult. Both patients and clinicians tend to discount cannabis as a possible cause of vomiting — and in a postoperative context, there are multiple other plausible explanations readily available. The result is a diagnostic delay that, according to a systematic review cited in the report, averages 4.1 years from symptom onset to confirmed CHS diagnosis, during which patients often undergo extensive and unnecessary testing.
In this case, the patient’s reluctance to disclose her cannabis use voluntarily compounded the delay. This pattern — patients withholding cannabis use history, sometimes due to stigma, sometimes simply because they don’t consider it relevant — is a recurring theme in CHS literature and reinforces the need for structured, non-judgmental cannabis screening as a standard part of clinical intake.
A call for perioperative awareness
The authors argue that as cannabis consumption continues to rise across age groups and regions, surgical teams can no longer treat CHS as an emergency medicine problem alone. Screening for chronic cannabis use should be built into routine preoperative assessments. Anesthesiologists, surgeons, and nursing staff all need to be familiar with CHS — its presentation, its diagnostic hallmarks (including the characteristic compulsion toward hot bathing for relief), and its clinical course.
Early recognition matters not only for the patient’s comfort and recovery but for healthcare efficiency: an unrecognized CHS case translates into extended hospital stays, unnecessary imaging, repeated failed medication trials, and avoidable cost. When the diagnosis is made promptly and cannabis abstinence is maintained, as this case demonstrated, recovery follows relatively quickly.
Patient education is equally important. Informing cannabis users — before surgery if possible — about the risk of CHS and the importance of honest disclosure can meaningfully improve perioperative outcomes and, over time, reduce the disease burden this syndrome quietly continues to generate.
