It should be noted that several personality disorders (especially borderline personality) include physical symptoms as well, and IBS-like intestinal disturbances are common. Note additionally the co-occurring symdrome for PD's that is the most common: which is substance "abuse", frequently including cannabis use. They are certainly self medicating, yet the societal climate throws a wrench in the subtle healing powers of cannabis.

I am not suggesting that the OP has a personality disorder, but IBS and other intestinal problems are common for those that do. The biology is connected.