A one piece self-supporting collapsible plastic urology drain bag 24 is mounted to an examination end 14 of a urology table 10. The pan includes a vertical inner end wall 28, a sloping outer end wall 34, a pair of opposite side wall 30, 32, and a bottom wall 36 through which a drain port 38 is defined. The inner end wall 28 of the drain pan is secured between plates 50 and 52. The drain bag is sufficiently flexible to allow a physician to collapse the outer end wall 34 against inner end wall 28 yet with sufficient plastic memory to enable the drain pan to return to its non-flexed position when the collapsing force is removed. A retaining means 56 is disposed on each end of the upper edge of plate 52. Each retaining means comprises a support means 58 and pin 60 arrangement. The pins 60 extend inwardly from their respective support means 58 along a line generally parallel to the upper edge of plate 52 away from the inner end wall 28, and sufficiently spaced from each other, such that outer end wall 34 can be releasably engaged between pins 60 and the inner end wall 28.