Fluid in abdomen and right lung. If ascitis, what tests do? Colonoscopy normal. CT normal (just show fluid). Barium normal. Severe ab pain. FBC normal

Complicated. There are several reasons to have ascites. The first could be liver failure from various reasons , including alcoholism, drug toxicity etc. could be right heat failure or generized edema from kidney failure . Continue follow-up with your doctor. Fluid should be removed to help with diagnosis and give you relief.