A Simple Colorimetric Method to Quantify Total Fecal Oil Using Oil-soluble Dyes in Laboratory Animals and Its Correlation with Liquid Chromatography-Mass Spectrometry Analysis.

We developed a colorimetric method for measuring the amount of oil in mouse stool after co-administering an oil-soluble dye. When the amount of oil in the feces calculated from the amounts of Sudan III and Oil Red O was plotted against the amount of oil detected by liquid chromatography-mass spectrometry, the graph was linear, showing a one-to-one correlation between two analyses. This method may be utilized to determine the efficacy of lipase inhibitors, or to assess fat malabsorption in vivo.