Crust and stains left in a toilet after flushing. They resemble wet bread bits.

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Dried bits of poo left on and around the butthole, formed as a direct result of waiting to long to wipe. Aforementioned "crusties" generally begin to form 10 or more minutes after final defecation (a.k.a. grand finale) has occurred.

Note: Flatulence exacerbates said condition as it tends to promote drying. Drying time dependent on velocity of flatulence, body temperature, external humidity, and PSI.