Sudden onset: pain radiating out from xiphoid process with back pain at same level and towards shoulders. what might cause this? history back spasms

Various causes: Acute pain in the pit of the stomach with back and shoulder radiation could be due to gastritis, pylorospasm, peptic ulcer, pancreatitis, gall bladder problems, etc. Xiphoid or sternal inflammation or pinched nerve in the rib cage are less likely. If you have abdominal tenderness, nausea, vomiting, abdominal distension or persistent pain, see your physician.