"Choline combines with fatty acids and phosphoric acid within the liver to form lecithin. It improves liver and gallbladder function and helps prevent gallstones." http://www.hepatitiscfree.com/lipotrope_book.htm
"lecithin(Pure lecithin is known as phosphatidyl choline)can normalise the low phospholipid to cholesterol ratios found in gallstone patients by increasing the ability of bile to solubilise cholesterol." http://www.healthreaction.com/web/articles/lecithin.htm