Hey Scope. I'm shocked that your doc suggested Imuran that quickly - you've only been diagnosed for barely over a month?? Imuran and Remicade are usually our very last options (other than surgery, of course). There are a lot of other things to try first.
First of all, what dose of prednisone did you start with, and how long were you at that dose? You may have not given it long enough to start working before you started the taper. (I've done 40mgs for three to six weeks before tapering, depending on how my symptoms are doing, though the longer you are on that drug, the craptier the side-effects are.) Also 5mgs every four days is a VERY fast taper. I wouldn't taper any faster than 5mgs per week. I'm not surprised you are still having symptoms.
If you have proctitis, then your colitis is only limited to the bottom few inches of your colon, which means that rectals are definitely your best bet. Is your Salofalk oral or rectal (I know it comes in both)? If you aren't on a mesalamine enema (Salofalk, Rowasa, etc), you should get on one ASAP. Also very helpful: cortifoam - rectal steroids in the form of a foam. I think for proctitis it is even more effective than oral steroids with none of the side-effects.
The combo that got my very first (very stubborn) flare into remission was oral mesalamine (brand name Asacol) 3x/day, nightly mesalamine enemas, and cortifoam in the mornings... and mine was proctosigmoiditis, which means mine went further up than yours does, so I imagine that combo would work well for you. After a few weeks I was able to drop the cortifoam and just do oral and rectal mesalamine.
If rectals don't get it, then you can experiment with other therapies (like LDN, dietary changes, etc). Many people find probiotics helpful.
Remicade and Imuran definitely work great for some people, but they don't always work (between 40-60% effective in clinical studies, actually), and many of us try them and find that our bodies cannot tolerate one or both. (We have a really bad reaction to the drug.) Oh, and do not believe your doctor when he says Remicade is only given with Imuran. Many people (including myself) have been on Remi without the Imuran. In fact, when you combine them is when the side-effects are the most dangerous.
Most importantly, make sure you are happy with your GI doctor. To me it doesn't really sound like your current one knows his stuff, so I would try going to a different doc if I were you.
Follow my story: ronnielee-fightingforit.blogspot.com
32-year-old single female (teacher)
Dx mild/moderate ulcerative colitis 1995
Dx severe ulcerative pancolitis 2011
Remicade, Asacol HD (4800mgs), Mesalamine Enema, MMJ