The collecting bag is intended for human body wastes and has a bag member (1) and a discharge portion (8) including a discharge opening (9). A first plate member (21) is positioned on a first film blank (2) forming part of the bag and a second plate member (22) is positioned on an extension (3e) of a second film blank (3) forming part of the bag. At least one of the edges (21b, 22a) of the plate members (21, 22) is provided with a fillet or chamfer (21c, 22c) extending in a part of the facing edges in a range of the thickness of the respective plate member.
