What would cause instant severe diarrhea followed by a vasovagal episode? it happens every few months always in the middle of the night followed by a trip to the er for dehydration and nausea.

Nocturnal diarrhea: Irritable bowel syndrome is a common cause of episodic sudden diarrhea but nocturnal episodes are not typical. Other causes of sudden diarrhea are intolerance to certain foods,beverages or medications. Infectious causes would result in more continual diarrhea. The vasovagal reaction is nonspecific. If attacks are common, consult a gastroenterologist for diagnosis and treatment. Tests will be done