What Causes Lack Of Appetite, Stomach Ache, Blood In Urine And Dehydration?

I recently have had some medical issues and had my gallbladder removed. before I had a colonoscopy showing nothing. after that is when some of my symptoms started. I than started having trouble eating. became full after 1 ro 2 bites of food. severe pain and extended stomach after eating. ive lost 20 pounds in less than 2 months even being hospitalized for peeing blood malnutritioned and dehydration. my symptoms are not improving. im seeing a gastro doctor but feel like I may need to get a second opinion. all the test have shown during a second colonoscopy was my bile duct was enlarged . excess amount of bile left . and damage to my esophagus due to a food allergy. im getting extremely weak and can only hold down small amounts of baby food after taking Phenergan and a pain med. how or what kind of doctor or where do I begin. my gastro just tells me to change my diet or go to the er. not taking into account im not eating its painful my stomach is extended and nausea and vomiting. I don t know what to do next