I somewhere red that people with IBS-D might have too much dopamin and serotonin and that it could be rather a functional problem than the wrong food (because I tried every option with my eating habits!). I have a friend who has to take stuff like ritalin and I red the package insert and how it works - it mostly reduces dopamin and serotonin releases. Could this be the answer? I know this is not a very paleo question but I'm pretty desperate.
dr. stein seems to agree. he does amino acid therapy. I know a big group of people trying it now for ulcerative colitis and crohn's disease.