This is a confusing one since it is an encounter code, that being said the main term you want to look up is Attention, then you will go to the sub-term of Artificial, under artificial the indentation of opening. Under opening there will be a list and you look for Urinary tract and then you can choose Urinary tract NEC (Z43.6), and then under that there is a list of types of ostomies such as, cystostomy (this is Z43.5), nephrostomy, ureterostomy, and urethrostomy which are all Z43.6. Hope this helps.