[Old and new data on diarrhetic diseases in childhood I. Etiology and pathophysiology].

Etiology and Pathophysiology. The present article is a comprehensive review of recent research results in the field of acute diarrhea. The most important new idea in contrast to older views is that almost all acute diarrheas are associated with a disturbance of intestinal bacterial homeostasis: overgrowth of the small intestine with apathogenic or pathogenic organisms is followed by changes in intestinal metabolism with increase in intestinal water and electrolyte secretion. Anaerobic organisms cause by enzymatic deconugation and dydroxylation of bile acids secretion of fluid into the small intestine and inhibition of fluid absorption from the large intestine. 10-OH-fatty acids, which are formed intraluminally by enzymatic hydroxylation of long-chain unsaturated fatty acids from the diet by similar anaerobic organisms, produce profuse secretion of fluid into the small intestine. The ability of numerous strains of E. coli to produce enterotoxin, which has a qualitatively similar action to cholera toxin, is now considered to be a major cause of infantile diarrhea. The separation of two completely different pathophysiologic mechanisms of E. Coli, the enterotoxic and the enteroinvasive action which are determined by extranuclear chromosomal material, is an important result of recent research. Overgrowth of the small intestine with different bacteria is followed by loss of actiivity of lactase, and later of all disaccharidases in the intestinal mucosa.