The clinical, pathologic and biochemical changes resulting from obstruction in the upper intestinal tract have been carefully studied by a number of investigators. It is known that a marked or complete pyloric or duodenal obstruction results in severe toxemia or death. The associated increased nerve irritability and the development of a syndrome usually designated gastric tetany have long been recognized. Experimental work along these lines has been concerned chiefly with the nature of the toxic agent, with the changes in blood chemistry, and with the mechanism involved in the production of gastric tetany. The cause of death in this group of cases also has received much attention. Various hypotheses have been advanced, based on experimental studies and on theoretic considerations, but we believe that the associated renal lesion has not yet received sufficient recognition or consideration. Clinically it has been observed that the body reacts differently to intestinal obstruction, depending