On the site of absorption of fat from the human small intestine.

The results of previous studies of the site of absorption of fat in the human small intestine using a test meal with a water-soluble reference substance have been criticized because of observations which have indicated that fat separates from the water-soluble marker in the stomach. It is now shown that the separation of fat and marker follows a sufficiently well-defined pattern to allow correction of the results obtained. The separation of fat and marker does not invalidate the authors' previous conclusions that the site of absorption of most of the fat fed to man has been the proximal jejunum.