I have been vomiting on and off for nearly a year sometimes it is in the evening a couple of times and other times its all day for a week I only get a week off now and the. They have tested all of the upper and lower GI system they scoped, barium study, colonoscopy and stomach emptying also did head .ct everything is clear. I noticed that serotonin is part of the medicines for vomiting so was wondering if my serotonin levels could causing my problem. I do have fibromyalgia aslo elhers danlos syndrome and sevre osteoarthritis. Please respond thanks