stones made of various substances, most often cholesterol or pigments, present in the gallbladder or the bile ducts which lead through the ampulla of vater and into the duodenum (the first of three sections of the small intestine closest to the pyloric valve at the exit of the stomach). these stones are most often asymptomatic. when they occlude the bile ducts, several problems can develop. choledocholithiasis, which is a stone in the common bile duct, can lead to inflammation and infection of the gallbladder (cholecystitis) which is a surgical emergency. cholecystectomy (or removal of the gallbladder) by laparoscopy is the solution for this. these people typically have an increase in their white blood cells, fever, and a positive murphy's sign. the exit for the bile ducts merges with the exit from the pancreas in 70% of people before entering the duodenum. when a patient has a stone which blocks this common exit, pancreatitis, or inflammation of the pancreas can happen, and this is the major cause of pancreatitis. this is seen by an increase in the blood of the enzymes amylase and lipase.