Hi and welcome to HCM.
GGT elevation is definitely caused by alcohol. Even 3 glasses of wine raise its level.
Stomach protruding as you say can be caused by many disorders and can be related to your liver damage
if you have it; it is called ascites
and means that here is fluid accumulation in your abdominal cavity. If you have bloating
which comes and goes then you should try to change your dietary habbits first,avoid smoking
,alcohol and fast food. If you have persistant enlargement in your abdomen then you should do ultrasound
as soon as you can to verify is there any mass or fluid collection.
WIsh you good health.