Improved extraction procedure for determination of bile acids in faeces

A simplified extraction procedure for bile acids from wet faeces, using methanol/hydrochloric acid is described. Extracts were analyzed by gas-liquid chromatography, thin-layer chromatography and an enzymatic assay, with 3 alpha-hydroxysteroid dehydrogenase. Recoveries of some stable bile acids, added to faeces, were studied; extraction efficiency was also investigated with a procedure using radioactive labelled bile acids given orally to patients. Resin treatment of faecal extracts, because of the sometimes hard colour of the extracts, resulted in a slightly lower recovery as determined by the enzymatic method. Recoveries were higher, using the proposed extraction procedure, than those obtained with extracts prepared by the standard procedure of Grundy et al [6].