Foley catheter /fō″lē/ [Frederick E.B. Foley, American physician, 1891–1966] , a rubber catheter with a balloon tip that is filled with a sterile liquid after it has been placed in the bladder. This kind of catheter is used when continuous drainage of the bladder is desired, such as in surgery, or when repeated urinary catheterization would be necessary if an indwelling catheter were not used. Sterile technique is used in placing the catheter. See also catheterization.