What Causes Fluid Around The Liver Along With Cramps Radiating To The Rectum?

My wife has a fluid build up around her liver that is causing severe cramps. All other tests from her CT Scan on her liver were normal. She is not even a social drinker, ruling out an alcohol related cause. The cramps start off like menstrual cramps and intensifies eventually hurting in her rectum. Any idea what this condition is caused and possible treatments?