Abstract: A test for determining hepatic function has been developed. This test uses oral administration of isotope labeled phenylalanine or tyrosine, particularly .sup.13 C-phenylalanine, in a rapid breath test. In the preferred mode, the breath sample is analyzed using a mass spectrometer and compared with a standard. The breath test provides a dynamic rather than static determination of hepatic function and can be used for both early and late stage liver problems.

Abstract: A method of treating patients with clinical disorder involving splanchnic disorders such as liver or gut dysfunction, the dysfunction being characterized by depletion of metabolic energy sources. The treatment involves the step of administering an effective amount of adenosine, or related nucleosides, to achieve and/or maintain normal metabolic levels of adenosine triphosphate (ATP) and/or its precursors in the patient's liver or other splanchnic organs. Administration may be as a total enteral nutritional diet, or as a dietary supplement. The invention includes a total enteral nutrition diet having nutritionally acceptable amounts of a lipid source, a protein source, a carbohydrate source, a vitamin source, and a mineral source, and an effective amount of adenosine to achieve normal metabolic levels of ATP and/or its precursors in ATP deficient organs of a recipient host.