Gastroenterologists and hepatologists are increasingly being referred patients with persistent, commonly quite marked, abnormalities of liver function. Many are picked up in some form of health screening. In western countries, once hepatitis C has been excluded and heavy alcohol consumption is thought unlikely, the diagnosis is probably non-alcoholic steatohepatitis (NASH), now the second or third commonest liver disease (after hepatitis C) in outpatient hepatology practice in North America. 1 Its importance was recognised by a Consensus Symposium organised by the US National Institutes of Health in Washington in December, 1998.