My sister (aged 79) has had an endoscopy, colonoscopy, sonogram, lung xray, etc., yet the doctors cannot find out why she has nausea and diarrhea (sp). About a year ago, she mentioned that her sense of smell and taste were not what they used to be. The only area not checked out has been her head. Could she have some brain disorder that could be causing this? The only thing they found in the hospital was blood clotting in her lungs. They have stopped looking for anything else. What should she do? She has been on various medications (including blood thinner Xerelto) for about 3 months. Could that have caused this malady?