The postprandial concentrations of free and conjugated
bile acids were measured in total content and micellar phase of jejunal aspirates from nine patients with steatorrhoea due to the
stagnant loop syndrome and from 11 normal controls. Aspirates from the
stagnant loop syndrome patients, but not from the normal controls, had a high concentration of free (unconjugated)
bile acids. There was a reciprocal decrease in the concentration of conjugated
bile acids, but total
bile acid concentration in the whole aspirate remained normal. Total
bile acid concentration in the micellar phase of intestinal content was reduced, indicating precipitation of
bile acids. These findings suggest that precipitation of unconjugated
bile acids, rather than passive absorption, leads to a reduced postprandial concentration of
bile acids in the micellar phase of jejunal content, and are consistent with the hypothesis that fat malabsorption in the
stagnant loop syndrome results from decreased micellar dispersion of lipolytic products.