A POSITIVE role of bile and bile salts in the production of diarrhea is indicated by the effects of bile duct manipulation on the occurrence of diarrhea in irradiated rats. The diarrhea characteristic of the intestinal syndromes of rats receiving high-dose, whole-body, or abdominal irradiation can be prevented or its time of appearance delayed by bile-duct ligation or bile diversion.1,2 When the bile is diverted from the intestine of rats receiving 1,500 rads of abdominal radiation, diarrhea does not occur, whereas it does occur when either rat bile or taurocholic acid is instilled into the intestine of these rats. By contrast, instillation of saline solution does not induce diarrhea.3
These observations may be interpreted as resulting from the presence of increased amounts of unabsorbed bile (bile salts) in the colon following high-dose, whole-body, or abdominal irradiation at a time when intestinal absorption is reduced or absent. Before examining