Ammonia tolerance test used to differentiate between ascites of cirrhotic and malignant genesis

Eighteen patients with ascites, 9 with cirrhosis of the liver and 9 with malignant disease, were subjected to the ammonia tolerance test by instillation of ammonia transrectally . Arterial blood samples were taken before and 15 and 30 min after the instillation to determine the plasma ammonia concentrations. The results show a significant difference in the plasma ammonia concentration between the two groups of patients after instillation of ammonia. Since the method is non-invasive, it is recommended as a screening test in the differentiation between ascites of cirrhotic and malignant genesis.