Although it can be for checking the outcome of possible sharting experience, most frequently it is when you desparately seek the nearest bathroom solely to wipe your ass due to a greasy bunghole feeling. Often an emergency wipe is needed in hot/humid conditions and/or not wiping well after one's last shit, as skid marks will frequently be evident on one's underwear or toliet paper. Due to this action being one of those "unmentionables" common to mankind, there are code words for an emergency wipe that include "E.W.", "Edward William", "Prince Eddie," & "Eduardo Guillermo" (for Spanish speakers)
Hey man, sorry about the interruption, I had to go see 'Edward William' (code that I just took an emergency wipe). Did the waitress come by yet?