Chanel West Coast's Coachella Bathroom Rules

Chanel West Coast is happy to TALK about dropping a deuce at Coachella ... as long as it's only talk because she has some very strict rules about the music fest and porta-potties.

We got the "Ridiculousness" star right after she did some pre 'chella prep at a tanning salon, and she spoke openly -- maybe too much -- about her phobia.

Check out CWC's revelation ... and a little explanation for her now infamous "Don't You Know Who I Am" incident last year at Coachella.