Can someone please advise me on modifer 51 and 59 for billing for colonoscopy and egd on same day or two different colon techniques used. For example 45385 and 45380, would you put at 59 on the 45380? What if colon and egd, 51 on the egd? I am being told conflicting things and it keeps changing. I bill the doctor portion and the ASC side as well. Thank you