It is a possible deformity though.

This is the only report of an adult I found (notice: NSFW images): http://www.casereports.in/articles/4/2/A-Rare-Presentation-of-Caudal-Duplication-Syndrome-in-an-Adult-with-No-Functional-Impairment.html

A 23 year old female presented to our OPD for correction of deformity of her external genitalia as she was going to get married. She gave history of double vaginal, urethral and anal openings since birth. She gave history of two separate streams of urine during micturition since birth with no history of urinary incontinence, retention or other urinary disturbances. She gives history of double anal openings since birth, with an anterior abnormal anus opening into the posterior portion of her vulva, whereas the second anal canal opened in the normal anatomical location. There was no history of any bowel habit disturbances.

Her only complaints at presentation were the presence of two small vaginal openings in place of a single vagina, with expected difficulty in marriage.

Ultrasound of pelvis showed uterus didelphys, with ipsilateral fallopian tubes opening into respective uterine cavities which continued as duplicated cervix opening into respective vaginal vaults separated by a longitudinal septum. There was duplication of urinary bladder with duplication of urethra but normal appearing single kidneys were visualised on either side with single ureters draining into their respective bladders. Other solid viscera appeared to be normal. Micturating cystourethrogram showed, duplication of urinary bladder with each bladder draining into their respective urethrae. Barium studies showed a normal foregut, but duplication of the entire colon draining into their respective rectums and anal canals.