• Clinical Data to Date

    The Use of Medical Cannabis in Gastroenterology 

    Research into the therapeutic efficacy of cannabis, its extracts, and refined phytochemicals has been an active area of study for over 40 years and is accompanied by a vast amount of anecdotal evidence and case reports of therapeutic benefit. The list of conditions that medical cannabis is alleged to treat continues to grow, but research is still lacking in many areas.  

    Although many patients report that it alleviates their symptoms, it remains unclear whether cannabis and its extracts are effective for treating GI conditions. Two major limitations to designing proper clinical studies are regulatory licensing hurdles and the lack of development and supply of a true placebo. 

    Despite a lack of high-quality evidence due to regulations, some research indicates that medical cannabis may improve GI conditions such as severe nausea, inflammatory bowel disease (IBD), and chronic pain. 


    Inflammatory Bowel Disease (IBD) 


    There is currently a large unmet need in the treatment of inflammatory bowel disease (IBD) with conventional medical therapy. Despite improvement in disease activity, many patients have persistent clinical symptoms that have significant impact on their quality of life. Patients have been seeking out alternative therapies (including cannabis) to help manage persistent symptoms associated with IBD (J.K., 2018). 

    Surveys of cannabis use in IBD patients in the United States and Canada have found that approximately 15% to 20% of patients currently use cannabis, and up to 40% have tried cannabis to relieve IBD symptoms. 

    These retrospective studies have shown that many IBD patients report cannabis improves symptoms such as pain, appetite, and diarrhea. In these studies, patients have used cannabis by both oral an inhalation routes (J.K., 2018)  

    Crohn’s Disease: 

    A small study was designed to determine if cannabis (smoked) could induce remissions in Crohn’s disease patients who were unresponsive to steroids, immunomodulators, or anti-TNF agents (Naftali et al. 2013). Clinical response was seen in 10 of 11 patients in the cannabis group compared to 4 in 10 in the placebo group. Three patients in the cannabis group were weaned from steroid dependency. Those receiving cannabis had improved appetite and sleep and no significant side effects. 

    Recently, in the first study of its kind, cannabis oil has been shown to significantly improve the symptoms of Crohn’s disease and the quality of life sufferers but, contrary to previous medical thinking, has no effect on gut inflammation (Naftali, et al 2018).

    In this randomized, placebo-controlled study, researchers from Israel have shown that cannabis can produce clinical remission in up to 65% of individuals after 8 weeks of treatment, but that this improvement does not appear to result from a dampening down of the underlying inflammatory process. Going forward, the research group plans to explore the potential anti-inflammatory properties of cannabis in the treatment of IBD further. 

    Recently, Dr. Naftali stated "There are very good grounds to believe that the endocannabinoid system is a potential therapeutic target in Crohn's disease and other gastrointestinal diseases," “For now, however, we can only consider medicinal cannabis as an alternative or additional intervention that provides temporary symptom relief for some people with Crohn's disease.’ (Naftali, et al 2018) 


    Ulcerative Colitis:

    Irving and colleagues assessed the efficacy, safety, and tolerability of once-daily oral CBD-4% THC (CBD-rich extract) for 10 weeks in patients with active ulcerative colitis (N=60) as an adjuvant therapy while on stable dosing of mesalamine therapy. Patients were less tolerant to the CBD-rich extract than placebo, and there were significant protocol deviations in the study. Both groups failed to reach the primary endpoint of clinical remission, and there were no differences in the rates of remission between the groups (28% for the CBD-rich extract and 26% for placebo). Per-protocol analysis showed improvement in patient’s global impression of change and a trend toward improved quality-of-life scores with CBD-rich extract use.

    Most recently, unpublished data were presented by Naftali and colleagues at the 2018 Digestive Disease Week. They evaluated the effects of smoking 2 cannabis (THC-rich) cigarettes daily or placebo for 8 weeks in patients with moderate to severe ulcerative colitis (N=28). In this study, medical cannabis use was associated with improved clinical disease activity scores and endoscopic improvement (reduction of Mayo endoscopic subscore from 2 to 1; P <.01). However, there was no significant change in CRP or fecal calprotectin in either group.


    Other GI Disorders & Symptoms

    The potential use of medical cannabis for pain management is also of great clinical interest. It is promising that vaporized cannabis augments the analgesic effects of opioids and cannabinoids and can reduce the dose of opioids used by chronic non-cancer patients (Lynch and Clark 2003; Abrams et al. 2011).

    Further, it has been shown to help those with nausea and vomiting. For instance, a review of 28 studies that included 1,772 participants suffering from chemotherapy-induced nausea and vomiting found a greater benefit of cannabinoids for the treatment of nausea and vomiting than an active comparator or placebo (Whiting et al. 2015). 

    The evidence for treating IBS specifically is sparse at this time. We’re beginning to see clinical experience suggesting effectiveness at reducing diarrhea and relieving abdominal pain, but more research is needed in this area. 

Enhancing lifelong health

The Canadian Digestive Health Foundation believes our ability to help establish, enrich and protect a healthy gut microbiota is the key to lifelong health