Had gastric bypass. egd clear. ultrasound shows sludge in gallbladder. can sludge still cause me pain in my right side and extreme nausea after eating?

Possibly.: Usually sludge in the gallbladder doesn't cause pain (gallstones can). However, it may be that your gallbladder isn't functioning properly. The best test to have done is a HIDA with cholecystokinin (a special nuclear medicine test that tells whether the gallbladder empties properly). Your primary care doctor can order this, or your surgeon. If positive, taking the gallbladder out can help.