What are gallstones? Gallstones form when bile stored in the gallbladder hardens into stone-like material. Too much cholesterol, bile salts, or bilirubin (bile pigment) can cause gallstones. When gallstones are present in the gallbladder itself, it is called cholelithiasis. Around 80% of people with gallstone symptoms will need surgery. Surgeons may remove your entire gallbladder (cholecystectomy), or just the stones from bile ducts. Techniques to remove the gallbladder include: laparoscopic cholecystectomy – 'keyhole' surgery.