A 2013 Gastroenterology and Hepatology study randomly assigned Crohn’s disease patients who didn’t respond to other treatments to smoke either cannabis cigarettes with or without THC. Study results showed complete remission was achieved by 45% of subjects in the cannabis group and 10% in the placebo group. Short term treatment with THC rich cannabis induced clinical remission and improved quality of life in patients with mild to moderately active ulcerative colitis.  A clinical response was observed in 10 of 11 subjects in the cannabis group (90%) and 4 of 10 in the placebo group (40%).