Hepatic encephalopathy is a frequent and debilitating complication of liver disease. The mainstay of treatment, lactulose, has been used since the 1960s, even without a strong evidence-base for efficacy. Currently, in the AASLD guidelines for hepatic encephalopathy, updated in 2014, lactulose is recommended as first line therapy for the treatment of episodic overt hepatic encephalopathy (Grade II-1,B,1 which means controlled trials without randomization, moderate evidence strength, strong recommendation)1. It's notable that there is a cost appeal of lactulose compared to alternative or add-on therapies such as rifaximin and this is considered in their recommendation.