The answer to your question is actually no, the use of medicinal cannabis in inflammatory bowel disease has not yet developed into a scientifically validated treatment protocol. IBD is notorious for waxing and waning, which makes it extra difficult to be sure of the association of various treatments with the symptom level. You may read anecdotal reports or find suggestions of various treatment regimens on the internet, but the situation is summed up by this quote from a review of the issue: "Epidemiologic data and human therapy studies reveal a possible role for cannabinoids in the symptomatic treatment of IBD, although it has yet to be determined in human populations whether cannabinoids have therapeutic anti-inflammatory effects in IBD or are simply masking its many debilitating symptoms." With regard to using just CBD the situation is even less clear. However the good news is that the evident lack of toxicity of CBD means it can be safely tried, and there is no evidence that taking even several hundred milligrams of CBD a day causes any adverse effects, although I would start with a much smaller amount. There is also no reason to not use CBD while taking conventional medications for inflammatory bowel disease, and I recommend against discontinuing pharmaceutical treatment in favor of CBD without checking with your physician.
Activating cannabinoid receptors has been shown to inhibit gastrointestinal fluid secretion and inflammation in animal models. Several studies indicate that cannabinoids in marijuana bind with cannabinoid receptors in the digestive tract, especially the small and large intestine.
Furthermore, both CBD and THC have been shown to reduce the inflammatory response in patients with autoimmune diseases, such as multiple sclerosis, lupus and celiac disease; both CBD and THC have also been shown to help alleviate pain.
"CBD may interact at extra-cannabinoid system receptor sites, such as peroxisome proliferator-activated receptor-gamma. This strategic interaction makes CBD as a potential candidate for the development of a new class of anti-IBD drugs."
"CBD targets enteric reactive gliosis, counteracts the inflammatory environment … in human colonic cultures derived from UC patients. These actions lead to a reduction of intestinal damage. Our results therefore indicate that CBD indeed unravels a new therapeutic strategy to treat inflammatory bowel diseases."