When they sew up your rectum, there's no hole anymore, so I don't think you'll be able to access that area. I had a fistula, and it disappeared when I had my colon and rectum removed. I wonder if once you're UC-free, you won't get those infections anymore? You could ask your doctor about
that. I'm glad you're looking forward to having an ileostomy and being rid of UC. After being sick for 12 years, you're going to feel like your 16 again!
Dx'd Crohn's in '99 at 28. Proctocolectomy and ileostomy in '06.
Disease-free, medicine-free, and very thankful to be healthy again :)