The impact that cannabis has on not one, but multiple illnesses is of incredible scientific and social benefit. Cannabis has been shown in some traditional medicinal practices to be highly beneficial for gastrointestinal conditions like ulcerative colitis and Crohn's Disease.
Clinical trials have found that cannabis was effective for patients with the disease, nearly half of which went into complete remission afterwards.  This was in addition to others being weaned completely from steroid dependency. Additionally, nearly all of the partients with active Crohn's Disease that participated in the clinical trial found that cannabis had a significant, positive impact.
A study conducted in Tel Aviv, Israel in 2011 found that 70% of the participants in the study showed an improvement in their condition, also prompting the Crohn's & Colitis Foundation of America to urge the US government to allow further research into cannabis as a medicine for gastrointestinal conditions like Crohn's. 
Unfortunately, additional trials with control groups and in-depth longitudinal studies have not been able to surface because marijuana is still illegal under federal law in United States and in Canada. Again, the illegal status is a great disservice to the Canadian public as they are not able to access Canadian specific science to the same extent as other drug that are prescribed for the same conditions. Even though other drugs often have a much higher rate of dependency along with a broader range of side effects.