Intermittent sharp, burning pain under right ribs x 3 days. radiates to back. no gallbladder. no other symptoms and pain worse when sitting. pancreas?

Several possibilites: Pancreatitis is quite serious, associated fever, sweats, vomiting, loss of appetite and progressive, not intermittent. You could be passing a retained gallstone, could be a hernia, cyst in liver, pleurisy, kidney stone. Okay to check in with your doc, take a friend with you. The exam and lab work, imaging will likely get to a diagnosis. Be well.

Poss Retained Stone?: In rare cases, when people have their gallbladder removed, they could have residual stones or form new stones in the main bile duct (common bile duct), and the symptoms can be very similar to typical gallbladder symptoms. Although this can cause pancreatitis, that is not usually intermittent sharp pain as you describe. You may need mrcp to rule out common duct stones. There are other possibilities.