Description: Segment 1 Dowling discusses bile salt composition. He shows slides of microcrystals in bile, before and after filtration. A further slide shows a test tube containing bile from a patient after cholecystokinin administration. Time start: 00:00:00:00 Time end: 00:06:12:00 Length: 00:06:12:00 Segment 2 Dowling shows a chart which details the composition of bile salts after centrifugation. A wall chart shows bile salt pool size in patients with gallstones and in control subjects. Time start: 00:06:12:00 Time end: 00:10:37:00 Length: 00:04:24:00 Segment 3 Dowling discusses some experiments on gallstone dissolution and shows the results in a series of charts and diagrams. Time start: 00:10:37:00 Time end: 00:14:33:00 Length: 00:03:56:00 Segment 4 We hear about an experiment which investigated bile composition in rhesus monkeys. A slide shows a glass chamber in which a gallstone is placed. A further chart illustrates the rates of gallstone dissolution of varying cholesterol content. Another chart illustrates the dissolution of gallstones in varying bile saturations. Some photomicrographs of gallstones are shown. Time start: 00:14:33:00 Time end: 00:19:55:13 Length: 00:05:22:13 Segment 6 A series of x-rays are shown to detail the results of treatment for gallstones. The complications of gallstones are discussed. Time start: 00:25:53:19 Time end: 00:30:23:09 Length: 00:04:29:15. Segment 7 Dowling discusses bile acid treatments and its complications. He summarises the lecture and concludes. Time start: 00:30:23:09 Time end: 00:34:56:09 Length: 00:04:33:00