Lactulose, a disaccharide sugar containing galactose and fructose, is used for the treatment of hepatic encephalopathy in veterinary medicine. It is also used as a laxative for the treatment of bowel diseases like megacolon, triggered from chronic constipation. The active ingredient, lactulose, works by reducing the ammonia build up in the blood. The large number of resident bacteria in the intestine consumes the unabsorbed lactose as their food and release lactic, acetic, and formic acid and carbon dioxide gas. These acids draw fluid into the colon, softening the stool. The acidification of the bowel contents draws ammonia from the bloodstream and locks it there to be emitted with the stool. This action aids the prevention of a form of dementia called hepatic encephalopathy.