Nocturnal Enuresis (3.5e Flaw)
From D&D Wiki
You just can't seem to get any restful sleep.
Prerequisite: Character must need sleep.
Effect: Whenever you sleep, you need to make a Fortitude save (DC 10 + ½ your character level) or be fatigued the next day due to wetting the bed constantly at night. This fatigue stacks and may result in exhaustion if combined with another fatigue factor.