"Cannabis has been used for centuries to treat a wide range of medical conditions, and studies have shown that many people with Crohn's disease use cannabis regularly to relieve their symptoms," explains lead researcher Timna Naftali on the origins of his research.

Researchers have long thought the anecdotal beneficial effects of cannabis on Crohn's disease was due to a possible anti-inflammatory effect, however no explicit underlying mechanism explaining this has so far been discovered. A study released earlier in 2018 hypothesized a new mechanism that could explain how cannabis reduces gut inflammation, but at this stage it has only been demonstrated in mouse models.

The new study from an Israeli team, as yet not peer-reviewed or published, set out to clearly identify the anti-inflammatory properties of cannabis by recruiting 46 patients with Crohn's disease. The randomized control trial administered half the cohort with an eight-week treatment of cannabis oil, and the other half with a placebo. As well as monitoring symptom severity, the researchers measured inflammation in the gut both endoscopically and via biomarkers in blood and stool.