Medical Marijuana for IBD

Research is lacking, but patients are interested

Medical marijuana being dispensed with a prescription.

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The use of medical marijuana (cannabis) is understudied in the treatment of inflammatory bowel disease (IBD). However, people who live with Crohn's disease, ulcerative colitis, or indeterminate colitis may decide to try marijuana to relieve symptoms.

One survey showed that about half of all patients included in the study were either actively using marijuana (12%) or had used it in the past for their IBD (39%).

Several states have legalized the use of medical marijuana, and others have made recreational (nonmedical) use legal. The specifics of these laws, such as how much marijuana a person can have in public or at home and how it may be sold, vary from state to state.

When thinking about marijuana, people with IBD will want to understand more about some of the research that has been done. Also important are the many different variables to consider before trying marijuana to treat the symptoms of their disease.

Medical Marijuana and IBD

The plant that's used to harvest the marijuana for medical or recreational use is called Cannabis sativa. It has long been used for medicinal purposes. However, it's also known to have psychotropic effects (what is often referred to as the "high"), which usually include a feeling of relaxation.

The reason marijuana may be useful in treating some conditions is because of the effect it has on the endocannabinoid system. The endocannabinoid system coordinates some body functions and can affect pain perception, inflammation, and appetite control.

One substance in Cannabis sativa plants that exerts an effect on the body is delta-9-tetrahydrocannabinol (THC). THC is the part of the marijuana plant that has psychoactive effects.

Cannabidiol (CBD) is another type of substance in the Cannabis sativa plant known to have various effects on regulating body systems. CBD does not have the psychoactive effects that THC does. CBD is available in a variety of products and is often marketed as a treatment for anxiety and to increase feelings of relaxation.

Both THC and CBD are in a class of substances called cannabinoids and are some of the more commonly studied chemicals found in marijuana. Cannabinoids act on the endocannabinoid system.

They are largely thought to lessen inflammatory processes in the body, but there is some evidence that cannabinoids may also increase certain types of inflammation. The effects are dependent upon factors such as which cannabinoid is used, how much of it is present (the dose), and how often it is used.

Cannabinoids are thought to act on the body, and the gastrointestinal tract, in specific ways. This is why marijuana is thought of as a potential treatment for the signs and symptoms of IBD.

However, many of the studies done on cannabinoids are on mice and not humans. Mice also have an endocannabinoid system and are often used in research. Not every effect of marijuana has been well studied in humans.

It's not known if all the effects that have been shown in mice might be expressed in humans. Some of the effects on the gastrointestinal system that have largely been studied in mice include:

Why People With IBD Consider Cannabis

The use of cannabis has not been well studied in IBD. No clinical trials have been done on marijuana and IBD in the United States. It's known, however, that patients are using it for their signs and symptoms.

A survey of 292 IBD patients gave some insight as to how and why they use marijuana. The study was done in Boston after Massachusetts included Crohn's disease on the list of medical conditions for which marijuana could be prescribed.

Sixteen percent of patients in this study used marijuana to treat their symptoms. Of those who said they used it, the most common reasons were treating abdominal pain and nausea. Most of the respondents said they thought marijuana did not help treat their diarrhea.

Even among the 49% of all patients in the survey who had never used marijuana, 52% said they'd be interested in trying it when it was legal to do so. Older patients were less likely to have ever used marijuana than younger ones.

Some of those included in the survey reported that they'd stopped using marijuana for their symptoms. Most commonly, people stopped because of the societal and legal risks.

Studies on Crohn's Disease

A couple of small studies have been done on humans to see the effects of cannabis and its components on Crohn's disease. However, they have not yet found these to be an effective treatment.

CBD and Crohn's Disease

The authors of one study looked at the use of CBD in treating Crohn's disease. They used previous research done on mouse models of Crohn's disease and CBD as a reason to begin working with patients.

The study was placebo-controlled, which means that some patients received the actual CBD treatment and others received a sham treatment. Neither the patients nor their doctors knew which one each patient received. Patients in the active treatment group were given 10 milligrams (mg) of CBD twice a day.

The researchers recruited 20 patients who had active Crohn's disease as measured by the Crohn's Disease Activity Index (CDAI). The CDAI is a tool that researchers use to assess disease activity. It uses the responses to 18 values to give a final score that may help researchers understand what the patient's disease is doing.

A score between 150 and 220 is defined as mildly active disease, between 220 and 450 is moderate to severe disease, and above 450 is considered severe. In this study, patients were included if their CDAI was over 200.

The patients were given their treatment for eight weeks and then followed for two more weeks after stopping it. At the end of the eight weeks, there were no differences found in any laboratory tests done, such as hemoglobin, albumin, and kidney and liver function tests.

The CDAI scores at the end of the eight weeks were similar between the group that received the CBD and the group that did not. The authors concluded that while CBD appeared to be safe, it didn't have any "beneficial effects" on Crohn's disease.

While some people in the study felt better, the CBD didn't improve inflammation. That means that the CBD didn't treat the underlying cause of the IBD. Inflammation in IBD that's not treated can lead to more serious complications.

There were a few reasons given to explain why CBD had no effect on the CDAI scores. The dose of CBD could have been too low, or the number of patients was too small to measure any effect.

Also, the authors think that other cannabinoids in addition to CBD might be needed to create the synergy that would actually treat Crohn's disease. Smoking marijuana may activate more cannabinoids, so the delivery method via CBD oil may also be a factor in the lack of results.

Marijuana and Crohn's Disease

A placebo-controlled study was done in Israel in 2013 at the Meir Medical Center, looking at how marijuana affected people with Crohn's disease.

Twenty-one patients with Crohn's disease were included. The patients included in the study had already gone through a few different forms of medications, which had not worked for them.

Some of the medications patients had tried included mesalamine, steroids, thiopurines (such as azathioprine), methotrexate, or anti-tumor-necrosis factor drugs. In addition, all the patients had active Crohn's disease. For the study, this meant that patients had a CDAI score between 200 and 450.

Patients were excluded who had more complicated Crohn's disease that included strictures, short bowel syndrome, abscesses, surgery within the past three months, mental illness, and either pregnancy or an intent to become pregnant. Patients were also not included in the study if they had previous experience with drug overuse or a history of cannabis use.

Patients received either cannabis cigarettes or cigarettes with no cannabis. The cigarettes were made by machine, so they were all the same, and each contained 11.5 mg of THC. The treatment time was eight weeks, and the researchers checked in with patients at weeks 2, 8, and 10 (which was two weeks after treatment ended).

The researchers looked for the patients in this study to go into remission, which they defined as a CDAI score of 150 or less. Other things they were looking for included a reduction of the CDAI by 100 points, a lowering of C-reactive protein levels by 0.5 mg, or improvements in quality of life as defined by the 36-question Short Form Health Survey.

While five patients in the study did enter clinical remission (as did one who received the placebo), this was not statistically significant. In other words, because of the nature of IBD, a certain number of patients will go into remission no matter what happens in the study.

Those five patients were not a large enough group for the researchers to say that giving marijuana to people with Crohn's disease had any effect on their disease. However, all of these patients relapsed after two weeks of stopping the treatment with marijuana cigarettes.

There are a few concerns over the results of this study. The first is that patients could figure out if they were receiving marijuana because they felt the "high." Cigarettes were used because they deliver the THC into the bloodstream more quickly, but smoking causes harm to the lungs.

Further, patients included in this research were carefully chosen. That's not out of the ordinary for a clinical trial. However, there were no patients with ulcerative colitis, indeterminate colitis, or any who had certain common IBD complications.

It should also be noted that several patients continued to receive steroids during the study and could not decrease them due to symptoms returning. One goal of effective IBD treatment is to reduce the use of steroids.

Lastly, the racial and ethnic makeup of the patients in this study was not included in the results. For that reason, it's not known how the results could apply to any other group of patients outside of Israel.

There is a concern that for the patients in this study, the effects of marijuana were masking the signs and symptoms of IBD and not actually treating them. In the end, the authors of this study don't recommend the use of marijuana as long-term therapy for people who live with Crohn's disease.

Studies on Ulcerative Colitis

A couple of small studies have been done outside of the United States to see the effects of marijuana and its components on ulcerative colitis. They have not shown effectiveness in reducing inflammation.

CBD and Ulcerative Colitis

A pilot study was done on CBD and ulcerative colitis. Sixty patients were randomized to receive either CBD or a placebo in nine centers in the United Kingdom. The patients were followed for 12 weeks. However, the goal of the study, which was to show if CBD had an effect on the inflammation that is caused by ulcerative colitis, was not achieved.

While the CBD did not affect inflammatory markers in this study, patients reported improvements in quality of life. This was a proof-of-concept study, and the authors point out several limitations, including the small number of patients and the differences in patient assessment between centers.

However, the researchers concluded that there should be more study of CBD in ulcerative colitis as an adjunct treatment.

Marijuana and Ulcerative Colitis

A randomized, placebo-controlled study published in 2013 looked at the use of marijuana cigarettes to treat ulcerative colitis. The study was done at a single center in Israel and included 32 patients with moderate to severe ulcerative colitis.

The Lichtiger Scoring Index and Mayo endoscopic score were the clinical tools used to determine disease severity. Patients on medical treatment for ulcerative colitis were included, but patients in the study could not change their therapy during the eight-week trial. The medications being used included 5-aminosalicylic acids, steroids, immunomodulators, and biologics.

Patients were randomized into two groups: One received marijuana cigarettes that contained THC, and one received cigarettes that did not contain THC (the placebo group). The cigarettes were made by machine to ensure they were similar in nature and contained the same amount of THC (80 mg).

There was a two-week observation period, followed by an eight-week treatment. The study concluded with two weeks of follow-up.

There were colonoscopies done at week 0 (before treatment started) and again at week 8 (when treatment concluded). This was performed to determine the Mayo score. In this way, the study authors could tell if there was any improvement inside the colon, such as healing of the inner layer of the wall of the colon.

There were some limitations in the study. The first is that smoking tends to have a positive effect in reducing symptoms in ulcerative colitis. It's unclear if the chosen mode of delivery, marijuana cigarettes, affected the patients in the study.

At eight weeks, the study was also quite short, and the number of patients was small. Additionally, it's not known if any improvements were from an overall effect that cannabinoids might have on the digestive tract rather than actually treating ulcerative colitis.

The authors concluded that the treatment was associated with "clinical improvement" for patients in the study. There was no "significant" improvement in the Mayo endoscopic score or the other tests (such as fecal calprotectin) that measure inflammation. The patients felt better, but there was no effect on colon inflammation caused by ulcerative colitis.

No discussion of the racial and ethnic background of patients in the study was included. Therefore, no conclusions can be drawn about how patients of various ancestry would be affected by the use of marijuana to treat their ulcerative colitis.

Seventeen patients continued with marijuana therapy for another year. Three of these patients needed a change in their medications (two required steroids). Of the 11 who had another colonoscopy at one year, all continued to be in remission (using the Mayo score).

The authors call for finding different delivery methods and for studies that include more patients for a longer follow-up period.

What's Next for Medical Marijuana and IBD

Currently, there isn't enough research into the use of marijuana to treat IBD. Recommendations can't be made until there are many more studies done that include larger groups of patients and patients with more diverse forms of the disease. That leaves patients without much information to go on to make decisions.

For marijuana to be effectively used to treat a complicated condition like IBD, it may need to be regulated. One possibility is that the substances in the marijuana that may help people with IBD are isolated. Those substances could then be standardized so that patients know what dosage to use and how much they are receiving.

For Those Considering Medical Cannabis

The reality is that people with IBD are trying cannabis to manage their IBD symptoms. In some states, medical marijuana is legal to treat IBD.

However, a physician needs to be consulted to get a license to use medical marijuana. That could be a gastroenterologist, or it could be another physician. Consulting with a gastroenterologist before starting to use marijuana for IBD is a good idea. Patients may be reluctant to do so, but it's important to let one's care team know about all supplements being used.

It must be noted that while marijuana is legal for either medical or recreational use in some states and some states have decriminalized its use, it is still illegal federally in the United States. 

Several other things that patients will want to consider when deciding whether to treat their IBD with marijuana include:

  • How to understand dose and purity
  • What the side effects may be
  • How it may affect work, social life, and finances
  • How it may affect other medications and treatments (including surgery)
  • Where to get guidance on dosage
  • Where to purchase quality products
  • The cost of marijuana (it is not covered by health insurance)
  • The legality of marijuana use in a particular state or country
  • The potential for adverse effects (such as cannabinoid hyperemesis syndrome)

It will be important for patients who are not experienced in receiving marijuana to get some information about its use. In areas where marijuana is legal, there may be several different forms to choose from, including cigarettes, oil, foods, and vaporizers.

Each method of delivery is different. Cigarettes affect the body more quickly, but edibles, while slower to act, could be more potent over time. A physician or a credible source such as the American Cannabis Nurses Association can help in understanding more about dosage.

There are also considerations of addiction and withdrawal. For those who use marijuana every day for a few months, there can be symptoms when the dosage is decreased. This is not usually life-threatening but can last for a few weeks. Some of the withdrawal symptoms can include cravings, irritability, anxiety, depression, headaches, and sleep problems.

A Word From Verywell

Some people who live with IBD are looking for ways to treat their disease's signs and symptoms. Pain, sleep problems, and nausea are a few reasons that some patients may look to marijuana for relief, which is understandable.

In the small, short study done in Israel, marijuana did improve quality of life. But this was under controlled conditions, which makes it difficult to apply the results to everyday life. There wasn't any evidence that marijuana treated inflammation.

The pros and cons of using medical marijuana are important to consider. There are potential harms as well as benefits. It may not be easy to talk about the use of marijuana with your care team, but this is important. Even if a gastroenterologist is not going to prescribe marijuana, they need to know what their patients are using to treat their IBD. 

12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.