Sixty marasmic children and fifteen normal age-matched controls were investigated for the absorption of fats and proteins. Their duodenal juice samples were also analysed for bile salts and microflora. A significant amount of malabsorption, with respect to both the dietary ingredients, was observed in the majority of the marasmic children. The levels of conjugated bile acids in the duodenal juice samples of marasmic children were significantly lower as compared with those of normal controls, while the reverse was true for free bile acids and bacterial counts. Significant correlations were observed between bile acid levels and fat absorption and also between microflora and free bile acids. The pathophysiology of malabsorption in marasmus is discussed in the light of these findings.