The data obtained in the study of these 3 cases of chronic ulcerative colitis, which were of different degree of severity, has indicated that in general the metabolic disturbance took a definite direction. The elimination of N in the feces may reach considerable magnitude and the amount of N excreted daily would seem to be directly proportional to the severity of the ulcerative process in the colon rather than to the amount ingested in the food. A decrease in the urinary excretion of N is seen in conditions of lowered nitrogen intake, starvation in the growing child, recovery from starvation, and during lactation. In many of these states there is a low value for the blood urea. A low value for the blood urea is a consistent observation in cases of severe chronic ulcerative colitis. In such cases, the concn. of urea in the blood varies from 8 mg. to 20 mg. per 100 cc. In cases of chronic ulcerative colitis, the N is lost in exudates and in blood from the ulcerative surface of the colon. The excretion of fat in the feces in these cases of ulcerative colitis was not in excess of that seen in normal subjects under the same conditions of intake. The role which the diarrhea plays in conditioning deficiency states in cases of chronic ulcerative colitis by virtue of decreasing the absorption of food through rapid transit or through changes in the character of the small intestine has probably been overestimated. It would seem that the greatest need of the body of a subject with ulcerative colitis is for protein. It would also seem to be of advantage to supply in abundance those minerals lost in excess in the feces and depleted from the body, as evidenced by their lowered concentration in the blood serum.