I have mid radiating back pain infrequently after eating. what tests do i need to see for gall bladder or ulcer?

Gallbladder disease: Gallbladder disease or passing a gallstone can feel like stabbing pain into your back. Fatty foods make it worse. Some positions can make it better. Your doc, will order ultrasound of abdomen/ruq, and get you referred to surgeon. Occasionally a tech hida scan is needed to make the diagnosis. Gastric/duodenal ulcers are diagnosed by egd. Good luck.