My crohns is mainly in my colon and rectum. I have had numerous fistulas. Remicade closed my first one. I am still on it...will be 5 yrs this Dec. I developed another one and I have a seton in it. My seton will be 3 this Sept. My surgeon and I decided against surgery on it at this point. If I have to delay my remicade, I will get a fistula to my bartholin gland...which is where my original fistula was. I am just really prone to those nasty buggers! The best thing you can do post op is soak in the hottest water possible as often as possible, but I'm sure with you being a nurse you are aware that this will help with the healing. If you have an abscess, I wouldn't be waiting until July 15 to get that taken care of...your surgeon can't get you in sooner?
Keep us updated on what happens. Good luck!