I suffered with proctitis too. Ironically, my disease stayed in the rectum and I suffered with it for twelve years. I believe the Colazal kept it from traveling further into my colon.
You can try the rectal meds, worth a shot. I became prednisone dependent and opted for surgery. During my years of suffering, I was on 6MP (eight years), Remicade and then Humira...all failed.
My GI doctor told me I had "moderate" proctitis but after surgery my surgeon told me I made the right decision and that my rectum was badly diseased.
Proctitis is very stubborn but people do have luck with the rectal meds. I have a friend who is doing very well on VSL#3 and Rowasa enemas. The best of luck to you.