yes . strange enough but most of the patient suffering from stomach upset , with a big load of files of all investigations including multiple gastroendoscopy are not diagnosed of any disorder. may be sometimes they are labelled irritable bowel syndrome patients .the root cause lies in anxiety. when person gets anxious it stimulates more adrenalin and may stress harmones in body which in turn stimulate the gastro intestinal speed . this leads to either loose motions or sometimes constipation .