Updated on January 28, 2019. Medical content reviewed by Dr. Joseph Rosado, MD, M.B.A, Chief Medical Officer
While medical marijuana can treat constipation and diarrhea, it can also cause either one. For patients who smoke or vaporize medical weed, these side effects are often non-existent. If you use edibles or oils to treat your condition, however, you may experience these side effects of medical cannabis.
Possible Side Effects of Medical Cannabis
Like other medications your doctor may prescribe, medical marijuana can cause several different side effects. For physicians, their goal is to provide you with medicines that offer you the best benefits and the least side effects.
Unlike prescription drugs, some medical cannabis doctors may recommend medical weed because of its side effects. If you cope with insomnia, for instance, your doctor might suggest medical pot because it can cause drowsiness and doesn’t pose the long-term risks of prescription sleep aids like Ambien.
How Does Medical Weed Cause Diarrhea and Constipation?
The cause behind diarrhea and constipation due to medical weed, is an area that’s gone unstudied. Some early studies suggest tetrahydrocannabinol (THC), one of several cannabinoids, slows down the digestive tract.
Another possibility is that edibles, as well as oils, may contain additional ingredients that affect how fast or slow your digestive system processes food. Another cannabinoid, cannabidiol (CBD), is considered a potential motivator for diarrhea.
With time, researchers may discover why medical weed causes diarrhea and constipation in some instances. While the legal standing of medical marijuana is one reason this topic has gone unresearched, another is due to the rarity of this side effect.
Signs of Diarrhea and Constipation From Medical Cannabis
What are Symptoms of Diarrhea from Medical Cannabis?
- Loose stool
- Abdominal cramps or pain
- Urgency to have a bowel movement
What are the Signs of Constipation from Medical Weed?
- Hard or lumpy stool
- Having fewer than three bowel movements a week
- Straining to express stool
- Feelings of being blocked
- Inability to empty stool from your rectum
If you begin to experience diarrhea or constipation, it’s critical to visit your physician.
Long-Term Side Effects of Diarrhea and Constipation
When they occur for brief periods, diarrhea and constipation don’t result in long-term side effects. If they last for weeks, however, you may need to change your treatment plan. Or, the symptoms could indicate a more serious problem.
What are some Conditions that Cause Diarrhea and Constipation?
- Crohn’s disease
- Celiac disease
- Irritable Bowel Syndrome (IBS)
- Colon cancer
- Rectal cancer
- Anal fissure
Long-term side effects of not treating your constipation include anal fissures, impaction, and rectal prolapse. The most substantial risk of untreated diarrhea is dehydration. No matter which symptom you’re experiencing, notify your physician as soon as possible.
How to Avoid and Manage Diarrhea and Constipation From Medical Marijuana
Because the medical community doesn’t have a complete understanding of why medical marijuana can cause diarrhea and constipation, there is no tried-and-true recommendation for avoiding or managing either cannabis-induced symptom.
In most cases, your medical marijuana doctor may recommend adjusting:
- Your diet
- Your strain of medical weed
- How you administer cannabis
- Your dosage of medical pot
Keeping a symptom tracker as you and your physician change your treatment plan is often helpful, as well.
Talk to Your Medical Marijuana Doctor About Your Diarrhea and Constipation
Whether you or a loved one is using medical weed, it’s essential you work with your medical marijuana doctor to ensure your treatment is offering you the maximum benefits — in most cases, medical pot does. If you’re experiencing unwanted side effects, schedule an appointment to discuss them with your physician, as they may be able to recommend useful changes.
Learn why some cannabis users experience diarrhea as a side effect and how to combat side effects to get the most out of your cannabis.
Cannabinoid Hyperemesis Syndrome
What is cannabinoid hyperemesis syndrome?
Cannabinoid hyperemesis syndrome (CHS) is a condition that leads to repeated and severe bouts of vomiting. It is rare and only occurs in daily long-term users of marijuana.
Marijuana has several active substances. These include THC and related chemicals. These substances bind to molecules found in the brain. That causes the drug “high” and other effects that users feel.
Your digestive tract also has a number of molecules that bind to THC and related substances. So marijuana also affects the digestive tract. For example, the drug can change the time it takes the stomach to empty. It also affects the esophageal sphincter. That’s the tight band of muscle that opens and closes to let food from the esophagus into the stomach. Long-term marijuana use can change the way the affected molecules respond and lead to the symptoms of CHS.
Marijuana is the most widely used illegal drug in the U.S. Young adults are the most frequent users. A small number of these people develop CHS. It often only happens in people who have regularly used marijuana for several years. Often CHS affects those who use the drug at least once a day.
What causes cannabinoid hyperemesis syndrome?
Marijuana has very complex effects on the body. Experts are still trying to learn exactly how it causes CHS in some people.
In the brain, marijuana often has the opposite effect of CHS. It helps prevent nausea and vomiting. The drug is also good at stopping such symptoms in people having chemotherapy.
But in the digestive tract, marijuana seems to have the opposite effect. It actually makes you more likely to have nausea and vomiting. With the first use of marijuana, the signals from the brain may be more important. That may lead to anti-nausea effects at first. But with repeated use of marijuana, certain receptors in the brain may stop responding to the drug in the same way. That may cause the repeated bouts of vomiting found in people with CHS.
It still isn’t clear why some heavy marijuana users get the syndrome, but others don’t.
What are the symptoms of cannabinoid hyperemesis syndrome?
People with CHS suffer from repeated bouts of vomiting. In between these episodes are times without any symptoms. Healthcare providers often divide these symptoms into 3 stages: the prodromal phase, the hyperemetic phase, and the recovery phase.
Prodromal phase. During this phase, the main symptoms are often early morning nausea and belly (abdominal) pain. Some people also develop a fear of vomiting. Most people keep normal eating patterns during this time. Some people use more marijuana because they think it will help stop the nausea. This phase may last for months or years.
Hyperemetic phase. Symptoms during this time may include:
- Ongoing nausea
- Repeated episodes of vomiting
- Belly pain
- Decreased food intake and weight loss
- Symptoms of fluid loss (dehydration)
During this phase, vomiting is often intense and overwhelming. Many people take a lot of hot showers during the day. They find that doing so eases their nausea. (That may be because of how the hot temperature affects a part of the brain called the hypothalamus. This part of the brain effects both temperature regulation and vomiting.) People often first seek medical care during this phase.
The hyperemetic phase may continue until the person completely stops using marijuana. Then the recovery phrase starts.
Recovery phase. During this time, symptoms go away. Normal eating is possible again. This phase can last days or months. Symptoms often come back if the person tries marijuana again.
How is cannabinoid hyperemesis syndrome diagnosed?
Many health problems can cause repeated vomiting. To make a diagnosis, your healthcare provider will ask you about your symptoms and your past health. He or she will also do a physical exam, including an exam of your belly.
Your healthcare provider may also need more tests to rule out other causes of the vomiting. That’s especially the case for ones that may signal a health emergency. Based on your other symptoms, these tests might include:
- Blood tests for anemia and infection
- Tests for electrolytes
- Tests for pancreas and liver enzymes, to check these organs
- Pregnancy test
- Urine analysis, to test for infection or other urinary causes
- Drug screen, to test for drug-related causes of vomiting
- X-rays of the belly, to check for things such as a blockage
- Upper endoscopy, to view the stomach and esophagus for possible causes of vomiting
- Head CT scan, if a nervous system cause of vomiting seems likely
- Abdominal CT scan, to check for health problems that might need surgery
CHS was only recently discovered. So some healthcare providers may not know about it. As a result, they may not spot it for many years. They often confuse CHS with cyclical vomiting disorder. That is a health problem that causes similar symptoms. A specialist trained in diseases of the digestive tract (gastroenterologist) might make the diagnosis.
You may have CHS if you have all of these:
Long-term weekly and daily marijuana use
Severe, repeated nausea and vomiting
You feel better after taking a hot shower
There is no single test that confirms this diagnosis. Only improvement after quitting marijuana confirms the diagnosis.
How is cannabinoid hyperemesis syndrome treated?
If you have had severe vomiting, you might need to stay in the hospital for a short time. During the hyperemesis phase, you might need these treatments:
- IV (intravenous) fluid replacement for dehydration
- Medicines to help decrease vomiting
- Pain medicine
- Proton-pump inhibitors, to treat stomach inflammation
- Frequent hot showers
- In a small sample of people with CHS, rubbing capsaicin cream on the belly helped decrease pain and nausea. The chemicals in the cream have the same effect as a hot shower
Symptoms often ease after a day or 2 unless marijuana is used before this time.
To fully get better, you need to stop using marijuana all together. Some people may get help from drug rehab programs to help them quit. Cognitive behavioral therapy or family therapy can also help. If you stop using marijuana, your symptoms should not come back.
What are possible complications of cannabinoid hyperemesis syndrome?
Very severe, prolonged vomiting may lead to dehydration. It may also lead to electrolyte problems in your blood. If untreated, these can cause rare complications such as:
- Muscle spasms or weakness
- Kidney failure
- Heart rhythm abnormalities
- In very rare cases, brain swelling (cerebral edema)
Your healthcare team will quickly work to fix any dehydration or electrolyte problems. Doing so can help prevent these problems.
What can I do to prevent cannabinoid hyperemesis syndrome?
You can prevent CHS by not using marijuana in any form. You may not want to believe that marijuana may be the underlying cause of your symptoms. That may be because you have used it for many years without having any problems. The syndrome may take several years to develop. The drug may help prevent nausea in new users who don’t use it often. But people with CHS need to completely stop using it. If they don’t, their symptoms will likely come back.
Quitting marijuana may lead to other health benefits, such as:
- Better lung function
- Improved memory and thinking skills
- Better sleep
- Decreased risk for depression and anxiety
When should I call my healthcare provider?
Call your healthcare provider if you have had severe vomiting for a day or more.
Key points about cannabinoid hyperemesis syndrome
- CHS is a condition that leads to repeated and severe bouts of vomiting. It results from long-term use of marijuana.
- Most people self-treat using hot showers to help reduce their symptoms.
- Some people with CHS may not be diagnosed for several years. Admitting to your healthcare provider that you use marijuana daily can speed up the diagnosis.
- You might need to stay in the hospital to treat dehydration from CHS.
- Symptoms start to go away within a day or 2 after stopping marijuana use.
- Symptoms almost always come back if you use marijuana again.
Tips to help you get the most from a visit to your healthcare provider:
- Know the reason for your visit and what you want to happen.
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
- Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
- Ask if your condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if you do not take the medicine or have the test or procedure.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.
Cannabinoid hyperemesis syndrome (CHS) is a condition that leads to repeated and severe bouts of vomiting. It results from long-term use of marijuana).