I think I have Iliotibial Band Syndrome, can i run?

It is great that you are icing your knee, and you should continue doing so for the rest of the week. No more than 15 minutes at a time for 3-4 times a day. If you only feel some moderate pain, and you feel that you are able to run through the half marathon, then you should be able to successfully finish the race. A mild case is not much to worry about, and you can recover afterwards without any significant long term effects.

The best way to tell whether your case it too severe to run is ask your own knee because it comes with a great warning system. If your pain becomes severe during your run, immediately stop. There is never any reason to run through severe pain.

I have to warn you that you will find that some people will not agree with my assessment that you should continue running through the pain, even when your pain is moderate. Those people are usually too careful, in my humble opinion. I'm sure that most sports therapists who are runners themselves will agree with me. Those who are not runners may disagree with me, and even tell you that running 13.1 miles is unnatural and bad for your body. In the end, you should use your best judgment because you know better than any of us.

Good luck~!

I had that same thing too! My gosh it hurt so so baddddd!!! I got it from basketball, it was really bad in March of that year. I iced it and took Advil and for the most part took it easy. It hadn't been bugging me too bad so I thought I was fine. Fast forward to the end of April- first day of track. After a bit over, I guess about 2 mi, my knee completely just gave out. The pain was excruciating! I could barely walk. Then it took longer to recover. My advice, just wait, unless you want to have to wait really long for it to heal.