A soft rubber pouch that was worn internally, that protruded out to join onto an externally worn belt. The end that joins the belt is sealed with a clamp that can be removed, allowing the device to be emptied without removing it. Interestingly, this patent talks about supporting the uterus, something I’ve seen many references to in early patents, and it explains that the lowering of the uterus causes the back pains women suffer during menstruation.
(via Google Patents – OCR text – has errors!) https://www.google.com/patents/US535980