Using cannabis can have a big impact on your physical and mental health—for better and, once in a while, for worse. That’s why it’s important to consult a healthcare provider before experimenting.
Here at GreenState, cannabis clinician Dr. Leigh Vinocur is here to answer your questions on healthy living with cannabis.
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Editor’s Note: The answer to this question is meant to supplement, not replace, advice, diagnoses, and treatment from a healthcare provider. Always consult a medical professional when using cannabis for medicinal purposes, and do not disregard the advice of your healthcare provider because of anything you may read in this article.
Q) Can cannabis help my ulcerative colitis?
A) This is an area of active research. But first, let’s discuss what ulcerative colitis (UC) is.
Ulcerative colitis and another bowel disease called Crohn’s disease are part of a chronic condition called inflammatory bowel disease (IBD) that affects the digestive tract. UC only impacts the large intestine (colon), while Crohn’s disease can affect any part of the gastrointestinal (GI) tract, from your mouth to your anus. Both conditions can be very debilitating, with symptoms such as abdominal pain and cramping, diarrhea, and blood in your stool.
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While UC only affects the lining of the colon, Crohn’s disease goes deeper and can affect all the layers of the intestines from the lining to the outside wall and can occur in patches throughout the digestive tract. This creates a cobblestone appearance with alternating areas of normal tissue and inflamed tissue; this is also referred to as skipped lesions.
IBD can also cause a disease outside the GI tract called extraintestinal manifestations (EIM), which can also be very debilitating. Issues may include such as joint pain/arthritis, anemia, hepatitis of the liver, kidney stones, eye inflammation, and pain called uveitis. While the exact cause is unknown and may be a combination of genetic and environmental factors, there is a component of an over-active auto-immune response where your body mistakenly attacks your healthy bowel cells. Diagnosis is usually made by colonoscopy.
The reason for the interest in cannabis use with IBD is because we know the endocannabinoid system (ECS) has many receptors throughout the GI tract. It is an integral modulator of many different functions of the GI tract, such as the motility of the gut.
The ECS, through Cannabinoid-2 (CB2) receptors, helps to maintain tight junctions in between the intestinal lining epithelial cells, establishing a healthy gut lining and barrier, preventing toxins and bacteria from getting into the bloodstream. This, in turn, also can help maintain a healthy microbiome in the GI tract. The ECS and CB2 receptors in the gut are expressed on immune cells there and help regulate and decrease inflammation. Animal studies done in the mouse model of colitis found cannabidiol, with its antioxidant and anti-inflammatory properties, reduced the inflammation in the gut.
Because of this involvement and ECS modulation in our GI tract, many IBD patients have turned to cannabis. In fact, a 2015 study found an increased prevalence of IBD patients using cannabis compared with the general population. Patients reported improvement in abdominal pain and diarrhea. Additionally, cannabinoids have immunosuppressive properties that can be beneficial to combat the auto-immune dysfunction contributing to IBD.
A randomized, double-blind placebo study (the gold standard of clinical trials) was done in 2015 with cannabidiol-dominant cannabis in ulcerative colitis (UC) patients. They found that while cannabis did not lead to a high percentage of remission and healing in these patients, the placebo group did have a greater proportion of worsening UC symptoms.
This corroborates a prior study with THC-dominant cannabis in mild-moderate UC patients. Researchers found that while patients clinically felt better, and felt their quality of life improved, they unfortunately did not have a decrease in their laboratory values of their inflammatory markers, nor did they see improvement or evidence of healing in the colon tissue during colonoscopy.
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The chronic inflammation seen in patients with IBD does put patients at higher risk for developing certain cancers, such as lymphoma, small bowel, and colorectal cancer. Additionally, this inflammation, along with other environmental factors, alters the gut microbiome, and we know that there is a correlation between your gut microbiome and the development and progression of colorectal cancer.
Therefore, another interesting area of cannabis research in IBD is related to cancer. A recent review study done in 2024 looked at the role of the ECS and cannabis in maintaining a healthy microbiome and its implications for future cancer therapies.
And while all of this sounds encouraging there are also studies that pose more questions than answers. A Canadian study found that self-administration of cannabis in IBD improved patients’ abdominal pain and cramping, as well as diarrhea. However, for some reason, these patients using cannabis for more than six months also ended up requiring more surgery but not more hospitalizations than those IBD patients who did not use cannabis.
Although therapeutic medical cannabis use with IBD is a potentially promising area of active study, as always, more research is needed. Additionally, it is always important to remember before you self-medicate and start a regimen of medical cannabis, it is critical to discuss this with your gastroenterologist or another knowledgeable clinician in medical cannabis science and therapeutics.
Got cannabis questions? Ask Doctor Leigh. Send your questions to GreenState’s Editor Rachelle Gordon at editor@greenstate.com and keep an eye out for new answers from Dr. Leigh Vinocur every month.
The response to this question was not written or edited by GreenState. The authors are solely responsible for the content.