Painless stomach bloating can be due to a number of reasons, from excess gas to constipation to more concerning causes such as liver or heart disease. In specific relation to liver disease there are several different causes of stomach 'bloating', two of the most significant are swelling or enlargement of the liver itself as well as a phenomena known as ascites.
Inflammation is the liver caused by infection or toxins (i.e. alcohol) can result in swelling of the liver and a feeling of abdominal fullness. Often when the swelling is acute, it will be accompanied by pain as the capsule of the liver is very sensitive to stretch. however, if the inflammation is more chronic than the liver can expand at a slow enough rate to cause painless swelling. another concern in a swollen liver is a cancerous mass, but this is rare.
Ascites is the accumulation of fluid in the belly for two main reasons:
-the liver is not producing the proteins necessary to osmotically keep blood in the circulatory system (i.e. albumin, a protein found in blood)
-the liver is congested with blood due to liver disease and this congestion is causing a backup of pressure in the circulatory system. the excess pressure effectively squeezes fluid out of the blood vessels and this fluid can accumulate in the belly.
If this bloating persists, it is important for you to see your doctor
as soon as possible for further evaluation and treatment. hope this helps!