The story was that she had a catheter inserted. It would have been attached to a bag which collected the urine, with the bag being secured to one of her legs. (Don’t ask me how I would know such a detail.) It would have been easily concealed by a dress. It enabled her to filibuster and pee to her hearts content - er - her bladder’s content.
Texas Sen. Wendy Davis dons urinary catheter for 11-hour abortion filibuster