Changes in gallbladder motor function during the female cycle--a risk factor leading to gallstone formation?

The gallbladder volume of eight women with stable cycles was determined by sonography. Furthermore, gallbladder contraction--following an orally administered fatty meal and the spontaneous refilling of the empty gallbladder--was quantitatively examined. The formula of a rotation ellipsoid, which has been proven to be adequately accurate in in vitro studies, was used for calculating the gallbladder volume. In the gestagen phase (21st or 22nd day) the intraindividual studies showed greater fasting volumes, higher residual volumes after contraction, slower gallbladder emptying, and retarded refilling of the empty gallbladder as compared to the estrogen phase (12th or 13th day). The hormonally modified contraction behavior and the differing course of gallbladder filling may play a major role in the pathogenesis of gallstone formation.