The act of having fecal matter on the outer ring of ones anus resulting in poopy butt syndrome. Poopy butt syndrome usually causes S.B.S. (Smelly Butt Sybdrome) and mostly I.B.S. (Ithcy Butt Syndrome.
1) Oh dude, my anus itches so bad. I am suffering from IBS because I have P.B.S.
2) After Remix got pounded in his rear he was suffering from P.B.S.