"Would rest from running also include staying away from cycling in your opinion?"
I am no expert. My experience was total rest - no cycling or any working the legs. I suppose if someone wants to try cycling and they feel nothing in the ITB then maybe cycling is OK to keep the fitness level. But I cannot imagine that cycling will not be working the ITB too. So what I did was total rest.
"With only 18 weeks to go taking 4 weeks off and then starting slowly is not really an option for a first timer marathon runner in my opinion" - I understand this reply to my previous post, but the injury will dictate the recovery time. In my experience it is better to rest it for longer, but be able to get back to 100% even for less weeks of training before the race, than to push too hard too soon and set yourself back totally.
It is a judgement. I think the total rest part is the most important. Maybe if the first couple of 2km runs after the total rest are 100% without any reaction, then if thee is a deadline the 'slowly' increase can be put aside and increase faster. But I think the first period of rest meaning total test is best not avoided.
But everyone has to decide and judge for themselves.
The cure is part of the question. As I said in the OP, I know running is not considered to be the original cause, but does anyone else find that even if you are apparently clear of them at the time, sometimes after a run they suddenly reappear? It cannot be a complete coincidence as they are there within an hour of doing a run.
I have had this and did lots of research. The most valuable thing I found was 'rest'. It is also the most unwelcome if you are pushing for a deadline. We all hate not to train and run. But what I read made clear that there is no real understanding of ITBS and conflicting advice. Some recommend stretches, but there is medical eveidence that suggests the ITB cannot really be physically 'stretched', so any benefit from stretching is probably limited. The research I did, and followed, said that rest is really the most positive thing you can do. IT has to be total rest. not just reduced running. Give it a total break for a month. Then start slowly, 2km max, maybe 3 times a week. Then build up, slowly. At the first sign of anythign wrong - stop and walk. Never push it. It will go.
In terms of a cause, the main suspect is running suface, camber, hills, and repetitive movement. The last of these is not to be underestimated. You may be fine doing hills, or road running, but not if you do it all the time. Mix your running, and you are more likely to avoid repetitive strains (IBS and lots of others too). And you will be a better runner too! So don't run the same course, same road, same hill every time. Change your training and mix it up.