*fat person farts* guy 1: eww, did you see that? guy 2:yeah, that fat guy just had an anal spasm
when a fat person farts and their ass proceeds to shake, rattle, and roll
"*fat person farts* guy 1: eww, did you see that? guy 2:yeah, that fat guy just had an anal spasm" What is the definition of "anal spasm"?