Cannabis has been a popular pain reliever for thousands of years, treating many kinds of illnesses, but research suggests that these illnesses can include an endocannabinoid deficiency. The different compounds found in marijuana are showing more and more medicinal benefits, but cannabis is the only drug shown to replenish the endocannabinoid receptors. Further investigation suggests this deficiency can block communication in the spine and peripheral/gastroinstestinal mechanisms causing conditions like headache pains, fibromyalgia, IBS, and muscle spasms.
Subsequent research has confirmed that underlying endocannabinoid deficiencies indeed play a role in migraine, fibromyalgia, irritable bowel syndrome and a growing list of other medical conditions. Clinical experience is bearing this out. Further research and especially, clinical trials will further demonstrate the usefulness of medical cannabis. As legal barriers fall and scientific bias fades this will become more apparent.
Original article: http://www.ncbi.nlm.nih.gov/pubmed/24977967