My Husband Has Been Having Fluid Removed From His Abdomen.

My husband has been having fluid removed from his abdomen. They call it acties (may not be spelled correctly). Last week made his 5th time for removal (11 liters last time). How long can this continue? He sees a heart Doc that says fluid not caused by heart - liver doc says not caused by liver - kidney doc says not from liver. What could be causing this fluid? He is a diabetic and does have chf.