It means diarrhea in Polish.
Typically considered a "low class" word, not to be spoken by the higher classes.
Casey i Ania maja sraczka zawsze jak zjedza burito.
(Casey and Ania always have diarrhea after eating a burrito)
Tata dostal w pracy taka sraczka ze caly dzien siedzial w ubikacji.
(Dad got such a diarrhea at work that he spent the whole day at the bathroom)