Oh and one more thing, to help prevent it then myofascial release of the itb helps. Use a foam roller or better still a rolling pin or cricket ball down the side of the thigh, keep doing until no longer painful. mine was so tight to start with I could not put weight on the side of my thigh, but by the end of it I could roll up and down on a cricket ball pain free.
RE - if it is ITBS then do not run at all - nothing! ITBS is a nightmare. I recommend volterol and smother you knee in it. also you could try an ITB strap.
If you keep running on it then the new collegen being produced to repair the ITB just gets broken down as it cant take the load bearing. minor itb takes a week, as there is not much new collegen in relation to strong itb. Collegen takes 2-3 weeks to become load bearing and 6-8 weeks to become fully remodelled and fully load bearing, each time you break more collegen down on the itb it takes longer and longer for the newer collegen to repair and remodel itself.
I had a nightmare with this a few years ago when I started training for my first marathon to the point I could not walk or drive, all because I didn't stop running and let it heal.
Thanks people, enjoyed seeing Jerusalem and Jordan, but the marathon was hell. it was about 3500ft elevation climb. After 13 miles I thought sod this, and walked up the steeper hills as it was not much slower than the people trying to run up them. I don't think I saw a flat section for the first 15 miles. I never knew Jerusalem was in the Judean mountains when I signed up for it!!!! Its a bit sole destroying when you can't actually run for the whole 26 miles. luckily it cooled down after the tela viv marathon the week before when it got cancelled half way through as it got too hot (circa 29 deg C), but still hot obviously.
lolabar - sorry to hear of your injury - that's shit! nice of you to pass your number on to someone.
manatbar - rest up and it will probably be ok - nothing to loose now with 2 weeks to go - may even be beneficial to do no running for 2 weeks and fully rest up,
Westy - don't bother getting a proper certificate - just make your own up - I have done it every time for my overseas marathons as they all require them. at first I made them quite good with a fake stamp - now I just fill them in and sign them myself. no one cares and don't even look at them - it just ticks a box. you could sign it micky mouse and probably get away with it. (but don't try that!)