Is it water?

 

Because, it can flow slowly in a stream, like silk, but can also smash against rocks, and make loud noises...

Shut-up I know I'm not good with riddlez

 

Anyways:

 

I am swallowed, though not digested. I pass through the body, though never leave it. What am I?

 

(I'm not sure if that even counts as a riddle >_<)

 

[Edit- Just noticed guy above me already said water (facepalm) I'll keep this here anyways, incase anyone want's to read it :3 ]