Studies with lactulose (galactose-fructose) and sorbitol indicate that they reduce neurologic abnormalities of hepatic encephalopathy. Nine patients greatly incapacitated by encephalopathy after portacaval shunting were able to continue relatively normal day-to-day living for 6 to 20 months without need for hospitalization because of neurologic symptoms. Sorbitol, a relatively inert sugar administered in a double blind prospective study was often as beneficial as lactulose. The mechanism for reducing neurologic symptoms is believed due to decreased absorption of ammonium and other nitrogen-containing compounds from the colon by the cleansing action of catharsis and lowering of the colon pH.