Description: Lactulose is a disaccharide sugar derived from lactose. Lactulose can be easily absorbed by the body and does not cause side effects. However, if lactose intolerance occurs, then lactulose should not be taken. Lactulose helps to maintain normal bowel function, including regularity and intestinal motility. It is commonly used to treat constipation and to prevent liver disease complications (hepatic encephalopathy).