Irritable bowel syndrome (IBS) is a common disorder that affects the large intestine (colon). Irritable bowel syndrome commonly causes cramping, abdominal pain, bloating gas, diarrhea and constipation. Unlike intestinal diseases such as celiac disease, ulcerative colitis and Crohn’s disease, irritable bowel syndrome does not cause inflammation or changes in bowel tissue or increase the risk of colorectal cancer.
Marijuana can be used to treat many of the symptoms of irritable bowel syndrome that are qualifying medical conditions under state medical marijuana laws. Marijuana “cools the gut.” It slows down the muscle contractions that move food through the stomach and intestines and reduces the secretion of liquid into the intestines associated with diarrhea (2). Marijuana also controls the muscle spasms associated with diarrhea.
Constituents in marijuana called cannabinoids interact with receptors (called CB1 receptors) in the enteric nervous system (the part of the nervous system that directly controls the gastrointestinal system) and with CB1 receptors in the brain. The cannabinoids in marijuana that contribute to its ability to treat the symptoms of irritable bowel syndrome include tetrahydrocannabinol (THC) and, possibly, cannabidiol (CBD). People with irritable bowel syndrome should use marijuana strains that contain a relatively high concentration of THC. THC binds to CB1 receptors on cells in the gut and brain and acts as an agonist to inhibit emptying of the stomach and transit of food through the intestines (3). CBD appears to have little effect on intestinal motility on its own, but it synergizes the effect of THC (4). Cannabinoids that activate CB2 receptors (agonists) like CBD may alter intestinal mobility under pathophysiological conditions (5).
1. Mayo Clinic, Irritable Bowel Syndrome.
2. Pertwee, Cannabinoids and the gastrointestinal tract, Gut (2001) 48:859-867.
3. Sanger, Endocannabinoids and the gastrointestinal tract: what are the key questions?, British Journal of Pharmacology (2007) 152:663-670.
4. Russo, Clinical endocannabinoid deficiency (CECD): Can this concept explain the therapeutic benefits of cannabis in migraine, fibromyalgia, irritable bowel syndrome and other treatment-resistant conditions?, Neuroendocrinology Letters (2004) 25:31-39.
5. Storr et al., The role of the endocannabinoid system in the pathophysiology and treatment of irritable bowel syndrome, Neurogastroenterology Motility (2008) 20:857-868.