Patients' knowledge of sublingual glyceryl trinitrate.

of stones from the gall bladder.3 There are several clinical implications. The long contiguous course of the cystic duct and common hepatic duct could explain why surgeons sometimes inadvertently leave a long remnant of cystic duct, which is reputedly a cause of the postcholecystectomy syndrome.4 Furthermore, the migration of stones from the gall bladder into the contiguous segment may explain transient episodes of jaundice and, with more severe impaction of stones, cause persistent obstructive jaundice, the so called Mirizzi syndrome. We thank Mrs H P Essel for her help. The study was supported by the South African Medical Research Council and the Staff Research Fund, University of Cape Town.