Spokesman George Arzt says Koch went back to NewYork-Presbyterian/Columbia hospital on Monday. He says Koch's doctor wanted the 88-year-old to get more treatment for the fluid in his lungs, which is causing shortness of breath.
Koch had been released from the hospital on Saturday after a week's stay. He had gone in Jan. 19 because of fluid in his ankles and lungs.
Doctors have told Koch to reduce his salt intake.
Koch also was hospitalized in December with a respiratory infection and in September with anemia.
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