If you have gallstones is it necessary to do surgery?

Not necessarily: Gallstones don't necessarily need surgery. If you are having symptoms and have gallstones, surgery is likely necessary.

Surgery or observe: If you are having no problems or symptoms you can leave the gallstone alone. If you are having upper abdominal discomfort, gas or bloating, upper abdominal pain or nausea after eating, then surgery would be indicated to remove the gallbladder.