Cannabis May Ease IBD Symptoms, but Evidence for Treating Intestinal Inflammation Remains Limited
For people living with Crohn’s disease or ulcerative colitis, cannabis may help relieve some of the symptoms that persist despite conventional treatment. The evidence does not yet show that medical cannabis can reliably control the intestinal inflammation that drives inflammatory bowel disease (IBD), however.
IBD is a group of chronic disorders in which abnormal immune activity damages the gastrointestinal tract. Crohn’s disease can affect any part of the digestive system, while ulcerative colitis primarily affects the colon and rectum. Symptoms may include diarrhea, abdominal pain and cramping, fatigue, fever, reduced appetite, and weight loss. Complications can include anemia, blood clots, inflammation of the joints, skin, eyes, liver, and bile ducts, and—particularly with long-standing ulcerative colitis—an increased risk of colorectal cancer. More information about the conditions is available from the National Institute of Diabetes and Digestive and Kidney Diseases.
What the research shows
Cannabis contains many biologically active compounds, including delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). These compounds interact with the body’s endocannabinoid system, which influences pain signaling, gastrointestinal motility, appetite, mood, and immune activity. Cannabinoid receptors are found in the nervous system, immune cells, and tissues lining the intestine.
Laboratory and animal studies suggest that endocannabinoid signaling can influence intestinal inflammation. In one mechanistic study, researchers found that intestinal P-glycoprotein helps export endocannabinoid-related compounds and limit neutrophil movement across the intestinal lining. The work, published in the Journal of Clinical Investigation, provides a biological rationale for studying cannabinoid pathways in gut inflammation, but it was not a clinical trial showing that cannabis treats IBD in people. Read the full primary research paper on intestinal P-glycoprotein and endocannabinoids.
Human studies have generally found more consistent improvements in symptoms and quality of life than in objective measures of disease. In a small 2013 placebo-controlled trial involving patients with treatment-resistant Crohn’s disease, THC-rich cannabis was associated with improved clinical symptoms, appetite, and sleep. The study did not meet its primary endpoint for remission, and its sample size was only 21 patients. The published clinical trial report describes the results and limitations.
A later randomized trial of 56 patients tested an oral cannabis oil containing CBD and THC. Participants receiving the cannabis preparation experienced improvements in clinical scores and quality of life, but researchers did not find significant changes in inflammatory markers or endoscopic disease activity. In other words, participants felt better, but the treatment did not clearly demonstrate that it had healed or substantially reduced intestinal inflammation. The CBD-rich Crohn’s disease trial concluded that cannabis should be studied further before it is used as an established treatment for inducing remission.
Symptom relief is not the same as disease control
This distinction is important. Cannabis may reduce pain, nausea, appetite loss, sleep problems, or the perceived severity of symptoms without suppressing the underlying inflammation. That could make a patient feel better while active disease continues unnoticed. For this reason, cannabis should not be viewed as a replacement for therapies prescribed to prevent flares, promote mucosal healing, or maintain remission.
Evidence for particular cannabinoid combinations is also preliminary. Some laboratory studies suggest that THC and CBD may have complementary or additive effects, but findings from animal models cannot establish an effective or safe dose for people. A 2025 mouse study, for example, reported benefits from combining a low dose of THC with CBD in chemically induced colitis; the results are hypothesis-generating rather than evidence that the same combination treats ulcerative colitis in humans.
What remains uncertain
Clinical trials have been small and have used different cannabis preparations, cannabinoid concentrations, routes of administration, and outcome measures. Many have also involved patients with difficult-to-treat disease, making it difficult to separate the effects of cannabis from changes in other treatments or from variations in disease activity.
A 2024 meta-analysis found that cannabinoids may improve quality of life and some measures of clinical disease activity, but not endoscopic findings or inflammatory markers. A broader systematic review published in 2026 likewise concluded that the evidence remains inconclusive, with mixed results and generally limited certainty. More rigorous trials are needed to determine which formulations, if any, provide meaningful benefits and whether those benefits extend beyond symptom control.
Cannabis can also cause adverse effects, including dizziness, impaired concentration, anxiety, sedation, and cognitive changes. THC may produce intoxication and can affect driving and other safety-sensitive activities. CBD is not risk-free either and may interact with prescription medicines. Product strength and purity can vary, especially outside regulated medical programs.
For people with IBD, cannabis is best considered—if at all—as a possible adjunct for persistent symptoms after standard treatments have been reviewed, not as a substitute for medical therapy. Anyone considering cannabis should discuss it with a gastroenterologist or other qualified clinician, particularly when taking immunosuppressive drugs, biologics, sedatives, or medicines processed by the liver. Patients should also seek prompt medical care for worsening abdominal pain, dehydration, persistent vomiting, heavy rectal bleeding, high fever, or rapidly worsening diarrhea.
