I have had flashbacks to a film I once saw on TV as a young lad. It stuck with me, but I’ve never been able to find it again.
It would have been on UK TV late night possibly channel 3 or 4 around late 90s. It felt older than that so may be 70s/80s. It was American, set in what would have been modern (dystopian) times. I recall a factory and someone managing to break in (very Soylent green style.) Inside, people (possibly just men) are on a conveyor belt, moving along. As they do, a small guillotine chops their male organ off and hey presto, they come out the other end as women.