Pain when I run

I hope someone can help me! I have been running for about a year now and used to be ok (5k in 30 mins). However, in the last 9 months I have got worse. When I run, I can usually go for about a mile then the pain starts to kick in just under the bottom of my right ribs(if I'm looking down). The pain is so great that a feel faint and can't walk properly. I have been to docs and they said rest, which I did for 6 weeks, but no joy. I have tried what I think is everything! Not eating, eating loads, no water, taking water with me, long warm ups, morning and evening runs (morning tends to be slightly better but this morning was awful!) I started off thinking it was a basic stitch but its not that, I know what they feel like and this is different! I hope someone can help! Thanks

side stitch: http://www.makeithappen.com/wis/readings/sidest.html

I had it on/off for about a year
try making sure that you breathe out on your left foot-plant and in on your right - this was the most useful thing I tried
I still get it occasionally running downhill in the later stages of long runs (i.e. when tired)
but it mostly just cleared up on it's own with increased experience/mileage

I had this also, along with some back pain for about six months, I saw a sports therapist who said that my psoas muscle had tightened due to the way I sat at my desk at work. He performed trigger point massage (which was painful) and got me into the habit of sitting with correct posture at my desk. Not sure if it was coincidence, but it did seem to do the trick. I do still get the odd twinge though.

Thanks guys! When you say breathe out when you plant left, does that mean take a breath in on right, out on left, in on right etc? That might be too quick for me?! I think I will book in to see a sports therapist this week. Thanks

I used to have a breathing pattern that was what I'd descibe as "forced 4 step":
I'd blow out forcefully on step 1, finish exhaling on 2, then inhale on 3 & 4
out of habit I always used to blow out as my right foot went down
when I switched to doing this on my left it definitely helped

I've also got a desk job, and I'm quite willing to believe my posture wasn't helping!