Bile acid malabsorption after jejunoileal bypass is less compensated for with a 1:3 than with a 3:1 jejunoileal ratio.

A previous study surprisingly showed that after jejunoileal bypass a ratio of 1:3 compared with 3:1 between the jejunal and ileal segment left in continuity resulted in a smaller synthesis rate, pool size, and postcibal jejunal levels of bile acids. These findings are reevaluated in the present study of 34 patients who either were waiting for or 3, 9, or 15 months earlier, had undergone bypass surgery with a 3:1 or 1:3 jejunoileal ratio. Compared with 3:1 bypass, the 1:3 bypass resulted in (i) greater reduction of the fasting bile acid pool, significant for chenodeoxycholic acid but not for cholic adic, (ii) less increase in synthesis rate of both bile acids, (iii) less decrease in relative content of taurine-conjugated bile acids in bile, and (iv) equal reduction of postcibal levels of bile acids in jejunum. We conclude that the increase in synthesis of bile acids compensates insufficiently for the excess fecal loss; the lower synthesis rate after bypass with a short jejunum relative to ileum in function may be due to an impaired stumulation of bile acid synthesis, the mechanism of which is unexplained.