[Diagnosis of steatorrhea]

Several indirect parameters of steatorrhea and quantitative measures of fecal fat excretion are described and in use as diagnostic tools for the detection and the differential diagnosis of malabsorption syndromes. The knowledge of their rationals, principles and also of technical aspects is an important foundation for both their application and interpretation, and thereby enables a rational diagnostic approach on a pathophysiological base. This synopsis of traditional, present and innovative, emerging methods for the diagnosis of steatorrhea covers the advantages of the respective techniques (fecal weight, fecal aspect, microscopy [Sudan stain], steatocrit, serum beta-carotinoids, titrimetric [van de Kamer] and gravimetric analysis, 14CO2-breath tests, NMR-spectroscopy, near infrared spectrometric analysis [NIRA], and 13CO2 stable isotope breath tests for fat maldigestion and -absorption), prerequisites for their application, and practical recommendations for specific situations. It may thus serve as a practical guide to the spectrum of 'coprophilic' and 'coprophobic', of 'low budget"- and 'high tech'-methods for assessing steatorrhea.