Marijuana — Not as harmless as you think

If you are a frequent pot smoker, or you know someone who is, this article is for you. There is a condition called cannabinoid hyperemesis syndrome (CHS) — its symptoms are similar to someone who has Crohn’s disease or disease of the gallbladder or pancreas.

Washington University gastroenterologist Elizabeth Blaney, MD, answers questions about this condition that doctors are beginning to see more of in their patients.

What symptoms would be indicators that the patient has cannabinoid hyperemesis syndrome (CHS)?

Patients with cannabinoid hyperemesis syndrome (CHS) may get a warning phase with nausea, decreased appetite and vague abdominal pain which can last for days before developing repetitive vomiting and diffuse abdomen pain. Symptoms sometimes improve with hot showers or baths. It tends to be worse in the morning. When in the acute vomiting phase, many patients will be sick enough to need emergency care and it can last hours to a few days before stopping. This can recur in a cyclical pattern over months.  

How are these symptoms different from someone who might have Crohn’s disease, IBD or a gallbladder problem?

Many GI disorders can have similar symptoms because the GI tract can only respond in a limited number of ways to many possible insults, which can lead to diagnostic dilemmas.  CT scans, ultrasounds and endoscopic procedures are sometime performed to help rule out inflammation disorders like Crohn’s disease or disease of the gallbladder or pancreas. 

In CHS we would expect normal radiology studies and scope procedures.  Lab testing is also usually normal in CHS, although patients can get dehydrated from the vomiting with resulting blood chemistry abnormalities or have a mild increase in the white blood cell count as a stress response.

 The diagnosis of CHS is based on the clinical history when other causes are excluded. One of the interesting unique features of CHS is compulsive hot bathing behavior. I know we have figured out the diagnosis when I go to visit a patient in the hospital only to find he or she has been in the shower all morning seeking relief of the symptoms. 

Do doctors know why cannabis use causes these symptoms?

This is still an area in need of further research, but there are theories. There are probably underlying genetic factors that make some people at risk for CHS.  We know the cannabinoid receptors can have paradoxical responses sometimes – e.g. relaxing effects vs. paranoia; euphoria vs. dysphoria.

While we usually think of cannabis as having anti-nausea effects, there can be an opposite response in some people with chronic use. The central nervous system has cannabinoid receptors and so does the nervous system in the gastrointestinal tract. Chronic use allows toxic levels to build up and cause dysfunction in the body’s processing of stressful stimuli. Essentially the body has trouble keeping things in homeostasis (stable state of equilibrium).

Proposed reasons why hot baths help alleviate symptoms is the warm water diverts blood to the skin from the gut, alleviating nausea or the changes in body temperature may help with the regulation of the homeostasis pathways. 

Are you seeing more patients with CHS as the use of pot is becoming more widespread and believed to be safe to use?

In the United States, adult cannabis use has more than doubled since 2011.  People generally recognize cannabis as having anti-nausea properties so diagnostic confusion can lead to patients self-medicating with cannabis, resulting in a vicious cycle.  Recognition of this disorder is critical because patients will not get better until they abstain from cannabis use.

Is this a recent phenomenon?  If so, do you think it is because the strains of cannabis are more potent now?

Modern-day strains have tripled in potency since 1995, so that is likely a factor in perpetuating the disorder. CHS was only described for the first time in 2004.  Many patients will have had problems for years before the correct diagnosis is made. Fortunately awareness of CHS among physicians is starting to increase, so we are seeing more recognition of the disorder.

What frequency of smoking pot is considered to be excessive and could lead to CHS?

Most cases of CHS are in daily cannabis users who have been using it for a year or longer. It appears men who use three to five times a day for two years or longer are at greatest risk. It can be seen in people who only use it weekly, particularly if past use was more frequent.

One theory is that the cannabis can be stored in body fat, so it may accumulate in the tissue and get released at irregular intervals, potentially under times of stress. That can make it confusing if the recent pattern of cannabis use is less frequent than daily. Sometimes that makes it hard for patients to see the direct link between cannabis use and vomiting episodes.

Obviously if someone has CHS, they need to stop smoking pot – what is the expected time to start to feel better?

Most of the symptoms resolve within three to four days of cessation of cannabis use. The mainstay of treatment is continued avoidance of cannabis because resuming its use can lead to recurrence of symptoms, which is widely reported to occur.

In acute cases, patients may need supportive care with IV fluids and medications to treat the severe nausea and vomiting. The optimal medications to treat nausea are being investigated with promising results emerging since traditional anti-nausea medications are not as effective for CHS as for other causes of nausea because CHS is not acting directly on the brain’s vomiting center. 

There is an interesting potential link between CHS and a disorder called cyclical vomiting syndrome (CVS), which can be viewed as similar to an “abdominal migraine.” Some patients with CVS resort to using cannabis for nausea, which could paradoxically be making things worse.

If a patient abstains from cannabis for at least one to two weeks and still has bouts of severe nausea, vomiting and abdominal pain, it would be beneficial to be evaluated for possible cyclical vomiting syndrome because there are other treatment strategies than can help these patients. 

For more information on CHS, or to make an appointment with Dr. Blaney, please call 314-747-2066.

Gastrointestinal Center
Center for Advanced Medicine
4921 Parkview Place, Suite 8C
St. Louis, MO 63110

Barnes-Jewish West County Hospital
Medical Building One, Suite 206
1040 N. Mason Road
Creve Coeur, MO 63141