I've been diagnosed with gallstones by ultrasound & been having severe gallbladder attacks but now my dr ordered a hida scan is that necessary?

Sometimes: Sometimes if the symptoms of your attacks do not correspond with gallstone pain, some physicians will order a HIDA scan to see if the GB is emptying properly. Most of the time if a person has gallstones and symptoms of right upper quadrant pain after eating, it would be justified to proceed forward with surgery with out a HIDA scan. You should speak to a General Surgeon.