By flexible endoscope I mean colonoscope, gastroscope, etc.
From this video I can see that an endoscope can swivel its tip while in place, kind of like a periscope.
But while moving axially, i.e. "telescoping" (is that the right word?) or "snaking its way in," or in other words, while being inserted, how does an endoscope turn?
Does it have to hit something (e.g. the interior wall of the colon), and only due to the resistance of hitting that something is it able to turn?
Or is it designed in such a way that it can turn in midair, without having to come into contact with anything, while maintaining the turning point at the same point in space as it snakes further in, à-la the classic computer game snake?