The Excretion of Nonprotein Nitrogen Substances by the Intestine

The excretion of water by the intestine has long been recognized as a useful therapeutic procedure, but little emphasis has been placed on the substances excreted with the liquid. The action of the saline cathartics is generally regarded as being due to the large amount of liquid that is abstracted from the blood through the intestinal mucosa by the hypertonic solution. Likewise, the more powerful purgatives are believed to cause excretion of a large amount of liquid which resembles the content of the small intestine and, as Cushny1states, these substances have been hurried through the bowel too rapidly to permit of their being taken up by the epithelium. The quantity of liquid that is normally poured into the small intestine every day by the various glands and organs of digestion and usually reabsorbed amounts to several liters, according to Meyer and Gottlieb,2and the composition of the