I just found this: (I cut and pasted the article)
Mysterious cannabis syndrome
A growing number of marijuana users are experiencing prolonged vomiting, a condition that may be related to the increased use and potency of the drug, finds Corryn Wetzel
DOCTORS are reporting a rise in people coming into emergency rooms with stomach pain and unrelenting vomiting. They compulsively take hot showers. Anti-nausea medication offers little relief. The unexpected culprit is cannabis – overconsumption can lead to what is known as cannabinoid hyperemesis syndrome (CHS).
“Many patients with CHS have violent hurling when they arrive to the emergency department,” says Sam Torbati at Cedars-Sinai Medical Center in Los Angeles. They often show up weak and dehydrated, and sometimes lose consciousness, he says.
Cannabis is commonly associated with relieving nausea – so much so that chemotherapy patients are often prescribed medications containing THC, the psychoactive compound in the plant. But in humans and some other mammals, high doses of THC can have the opposite effect.
CHS is a relatively newly defined condition, first described in a handful of cases in Australia in the early 2000s. There is no blood test or scan to determine whether someone has the condition, so doctors instead look for a combination of symptoms including unrelenting nausea, bouts of vomiting and stomach pain. The intensity of this illness has led to the informal advent of a new word – “scromiting” – describing episodes where people are simultaneously vomiting and screaming in pain.
“The cause of this syndrome is unknown,” says Linda Parker at the University of Guelph in Canada, but it seems to be limited to long-term and high-dose users – so people won’t come down with this condition after a single toke.
CHS has a series of escalating phases, which can last days to years. A loss of appetite builds to the “hyperemetic phase”, which includes persistent, painful vomiting. This is usually when people begin compulsively bathing in hot water, which may offer temporary relief by diverting blood flow from the abdomen to the skin or possibly by activating a part of the brain called the hypothalamus, which is involved in both temperature regulation and appetite, among other things.
A growing problem
Though still rare, the prevalence of CHS has soared in the past decade. For example, one study found that the rate of emergency room admissions for it in Ontario, Canada, increased 13-fold from January 2014 to June 2021.
CHS shows up unpredictably, which makes it even trickier to spot. Decades-long marijuana users can develop CHS late in life, while some young people are coming down with the condition after a few years of heavy smoking.
Mounting research suggests one reason for the increase in cases may be greater access to marijuana, from vapes to edibles. In Colorado, there was a 29 per cent increase in vomiting-related emergency room visits in the five years following legalisation of the drug for recreational use.
A similar pattern has played out in Alberta, Canada. After marijuana was legalised in the province in 2018, the rate of CHS-related emergency room visits went from 15 per 100,000 people, to 21 per 100,000. In 2020, it jumped to 32 visits per 100,000 people across all age groups. For those aged 16 to 24, the rate climbed to 600 per 100,000 individuals.
One reason that CHS is more common among young adults may be because they consume the most marijuana. Another factor may be potency. Cannabis available today contains more than 10 times as much THC, on average, as it did in the 1970s.
Doctors can manage some symptoms with medication and intravenous fluids, but the only “cure” is cutting out cannabis and waiting for symptoms to subside, which may take months.
Rewiring the brain
Some find temporary relief from creams containing capsaicin, the active ingredient in chilli peppers, applied to the arms and belly. Experts think this warming sensation, similar to the effect of taking a hot shower, activates a receptor in the stomach that can calm nausea and vomiting.
Experts don’t know the exact mechanisms behind why cannabis can trigger this illness, but they agree that THC is to blame. The compound binds to receptors in the endocannabinoid system, which regulates sleep, appetite, mood and more. “We currently believe that CHS may result from chronic overstimulation of endocannabinoid receptors in the body, leading to derangements in the body’s intrinsic control of nausea and vomiting,” says Torbati.
Long-term, heavy cannabis use “can change how our brains regulate nausea and vomiting”, says Marieka DeVuono at Western University in Canada. “While much more research is needed to understand the link, it seems likely that endocannabinoid system impairment is underlying CHS.”
Marijuana users can lower their chance of developing CHS by taking the drug less often and reaching for less-potent products. There is some evidence that using products with cannabidiol (CBD) – the non-intoxicating part of the plant – could help prevent THC-induced nausea.