Diagnostic significance of the sudan III staining for fecal fat.

To evaluate the diagnostic significance of the Sudan III staining for the fecal fat, the quantitative relationship between the number of fecal fat droplets examined microscopically and the amount of the fecal fat determined chemically was examined. In 43 out of 60 cases, the results of the chemical determination and the microscopic examination were in agreement and the accuracy was 72 percent. On the other hand, the false positive cases totaled 9 out of the 24 cases (37 percent) and 8 out of 9 false positive cases were diagnosed as showing a slight increase. In contrast, the false negative cases were only 2 out of 36 cases (6 percent). In addition, the comparative study of the various procedures of the Sudan III staining indicated the importance of the processing with acid and heating even in cases of steatorrhea caused by pancreatic insufficiency.