Lithogenic index of bile after jejunoileal bypass operation for obesity.

Lithogenic index of cholecystokinin-stimulated, fasting, duodenal bile was determined in 12 obese patients before and 1-2 months after end-to-side jejunoileal bypass operation, either including 37.5 cm jejunum and 12.5 cm jejunum and 12.5 cm ileum or 12.5 cm jejunum and 37.5 ileum. The index did not change significantly after bypass with short ileum, whereas a four-fold, significant increase was found after bypass with long ileum. Surprisingly, the results may suggest that the lithogenicity of gallbladder bile increases when the length of the functioning ileal, relative to the functioning jejunal, segment in jejunoileal bypass is increased.