A patient with longstanding alcohol abuse disorder presented with subacute abdominal pain with increasing girth, and acute severe diarrhoea. Diarrhoea was due to concurrent acute bacterial pancolitis which resolved with treatment. Ascites with high serum albumin-ascites gradient was diagnosed, secondary to recent-onset portal hypertension, due to acute alcoholic hepatitis. Examination, laboratory or imaging stigmata of liver cirrhosis were conspicuously absent, and no alternative explanation other than acute alcoholic hepatitis was found. Thus, acute alcoholic hepatitis can rarely cause marked portal hypertension.