What is the cause of frequent urination outside dibetes?

Many causes: I will answer for a male. Most usually is secondary to excessive fluid intake. Other causes that of prostate enlargement not allowing proper bladder emptying. Other causes "spastic" or neurogenic bladder. Rare cause is a hormonal condition called diabetes insipitus (not same a the diabetes you are accustomed to), and finnally an unkown urinary tract infection.

UTI: Urinary Tract Infection most likely. Excessive fluid intake, or (in men) prostate problems also.