A pouch comprises a flexible bag having an opening at one end, and a safety valve arranged inside the bag to substantially prevent the content of the bag leaving through the opening. The valve comprises a first pair of sheets and a second pair of sheets that are bonded together locally at a plurality of spaced-apart primary bonding points, and a third pair of sheets, the first, second, and third pairs of sheets being bonded together locally at a plurality of spaced- apart secondary bonding points. The distance between the primary bonding points and the distal end of the sheets of the second pair of sheets varies along a transverse axis (Dt) of the bag. A further transfer valve permits a portion of the urine to be transferred to a separate detachable pouch, which may then be transported, for example for diagnostic purposes.
