The gallbladder should be viewed as a hormonally responsive organ whose normal physiology may be altered by conditions ranging from intestinal disease to pregnancy. Disorders or conditions characterized by altered gallbladder motility predispose persons to gallstone formation. Recent studies of gallbladder sludge and the gallbladder motility of gallstone patients suggest that localized processes within the gallbladder may be critically important in gallstone formation. No unifying disturbance of motility characterizes gallstone patients, perhaps because mechanisms of gallstone formation are many and diverse.