What Causes Abdominal Distension?

My stomach has been distended and hard as a rock around to the sides for several weeks. Sharp pain in my kidney area. I have cirrhosis of the liver of unknown etiology, have quit drinking for several months now. Feels like stomach wants to pop every time I eat or drink anything and is painful all the time. Severe edema in both legs, ankle, feet. Goes down some when I stay off feet. Taking Lasix and 5 mg prednisone.