Hi and welcome to HCM.
Not much. This isnt something unusualy. He obviously have enlarged liver(this is explained to patient like swolen abs) but it means that doctor felt enlarged liver over his abdoinal muscles.
His symptoms and raised liver enzymes are associate dwith this. Now he shound find out the exact cause. In most cases this is tempray liver damage
caused by alcohol intake, gallbladder
stones, viral hepatitis
or some autoimmune disorders
. Other possible causes are more serious but much more uncommon at his age.
HE will do ultrasound
probably and everything would be clear then. I am sure this will be fine. Just be patient and follow doctors instructions.
WIsh you good luck.