Hi all.

I am a very active person. I train at the gym 5-7 times a week as well as doing kickboxing 5-7 times a week.

Just recently, I have started to get an intense stabbing pain in the muscle, starting from my ribcage, down to my right hip-bone whenever I run for long periods. The pain is much more intense than a "stitch" or a cramp, it actually feels like someone has stabbed me with a knife. I have to stop running immediately, and then go and sit or lie down, and the pain still doesn't go away until I have been lying down for longer than 15 minutes. Stretching the area doesn't help either, nor does massaging it.

The pain is gradually getting worse, and I can't run for as long as I used to. I would run for half an hour before the pain started. Now I can barely run for 10 minutes before the pain starts.
Other exercise is fine so far. I know that running is the cause, but I don't want to stop. I can't stop. I need to run.

Does anyone have any suggestions on what I could do? My blackbelt grading in kickboxing is coming up, and I have to run 5km in less than half an hour as a pre-requisite to get my black belt.

Any help would be great.

Could be a kidney stone.