The US and UK versions of Part 3 were heavily cut to avoid an NC-17/18 rating. The "Unrated" cut exists, but in many regions, the Indonesian subtitle track is often paired with the most complete, uncensored international master print. If you find a Sub Indo version, you are likely watching the pure, unfiltered Dieter Laser meltdown.
Even by Human Centipede standards, Part 3 pushes boundaries. It is important to note that this film is notorious for the following elements, which are fully preserved in the release: The Human Centipede 3 Sub Indo