In a previous paper1were reported studies of the laxative effects in healthy men of wheat bran and an acid-extracted product called "acid washed bran." These studies showed: (a) that wheat bran and "acid washed bran" possess demonstrable laxative power when tested on healthy men subsisting on known carefully controlled diets, (b) that there is a quantitative relationship between the fiber content of the diet and the degree of laxation prevailing in healthy men, and (c) that the laxative value of bran and bran products may be estimated fairly accurately from the fiber content. In view of the objections on the part of certain clinicians2to the use of bran as a laxative, it becomes of importance to determine the limitations, if any, of these reactions, which were the results of studies on healthy men. It was believed that a study of the actual laxative performance of patients