Ulcerative Proctitis is still colitis. Meowmix is right, how each type of colitis is diagnosed is by which part of your large intestine is inflammed. I was originally diagnosed with proctitis and it progressed to left sided colitis. (I was told by a locum once that my proctitis was not serious like UC. I believed her. What a mistake.) Any inflammation and bleeding is bad as far as I am concerned. And the severity of this disease is different for everyone. I know a woman in my hometown who has been in a flare with proctitis for four years now. How is that not serious???
As for treating proctitis, it is so important to use rectal meds. I use salofalk suppositories. Others use enemas. What works for one, may not work for another. Oral meds won't necessarily reach the inflammation.
Good luck.