A nice long soundscape that starts with an interior perspective and flips to an exterior perspective at 3min 20seconds.
They both have lots of gurgles, but there's a digestion and safe vore versions:
Safe vore: https://www.weasyl.com/~themonsterchow/submissions/1976687/inside-and-out-pov-external-vore-audio
Digestion: You are here