Is ascites always cancer?

No: BUT Ascites is serious and needs to be medically evaluated. Take care.

No: Ascites is frequently associated with tumors such as ovary which spread to omentum causing a release of a permeability factor that causes weeping of fluid from peritoneal surface to produce ascites. The latter also occurs during portal hypertension with cirrhosis of the liver resulting in fluid filling the peritoneal cavity. Rare infections such as TB peritonitis is associated with ascites.

Here are some ...: Most common is still related with liver cirrhosis from alcohol and hepatitis besides extensive peritoneal cancers like those from colon cancer, pancreatic cancer, liver cancer, ovarian cancer, etc. So, it's not always from cancers alone. In short, any disease conditions causing portal vein blockage or peritoneal reaction resulting in peritoneal fluid secretion/exudation will produce ascites...