Hi and thanks for your question, with such extensive evaluation and testing you have gone through, when no organic source of disease is identified, what you experience falls into a diagnostic class of disease called Irritable Bowel Syndrome (IBS). This is a very common condition and arises due to some abnormalities in the motility of the intestines. Treatment of IBS is both medical and also involves life style changes. These include, drinking a lot of water, taking much vegetables and fibres, avoiding late meals, avoid foods containing lots of gas. Exercise has been proven to relieve these symptoms. Some drugs could be introduced if symptoms really get worse like Spasmolytics (Spasfon), and motility regulators (Motilium, Debridat). Your treating physician shall be best placed to give you an appropriate and drug at an appropriate dose if need be. Thanks and best regards, Luchuo, MD.