How to code catherization in office

I have a lady who came in post op for problem other than her what she had done for surgery.

Her diagnosis now is urinary retention and cystitis.

She had an office visit and urinalysis. The doctor did catherization for residual urine and then after exam saw her in his office.

What code in addition to the E/M visit do I use for catherization for residual urine. The HCPCS or the surgery codes in the E/M?

Thank you

Karin Bowles
Gynecology