After many doctors and years of every conceivable test from both ends. I saw a medical doctor who also practiced alternative medicine and he suspected Glutin Intolerance.
He took a blood test and glutin antibodies showed up and told me to eat a glutin free diet. So simple.
Years later I learned that I have had Lyme disease for years that triggered my digestive and other problems. Lyme is not always transmitted by tick bite, but, also sexually and blood transfusion. Some carriers of Lyme have no symptons.
My help with health problems comes from Naturopathy although I still use conventional doctors on a limited basis.