Anyway, I'm a former HS and college runner who has recently moved up to running longer races. I'm really enjoying it. Unfortunately, I've been hit with a moderate to severe side stitch in every race I've run over 10k (3, all this fall). I almost never had side stitches before. I would get the lactic acid feeling in my stomach, but this is different. It's more of a tightness and discomfort that leads to being able to breath properly.
Here's my latest example. I ran my first half marathon this weekend. I hydrated a lot the day before, ate a large pasta dinner the night before, and drank more water and a cup of coffee the morning of. The race was at 9am. I did a gentle warm-up, and a few relaxed strides. The pace was very easy the first few miles. The the leaders surged and I went with them. My legs felt great and I wasn't breathing hard. However, within a mile I had a side stitch that made breathing difficult. I forcefully exhaled for a while, which helped some but not much. I was able to gut it out, but ran 4-5 minutes slower than my workouts had suggested. I also felt quite strong, except the stitch which led to a lack of oxygen.
It's two days later, and my abs are sore. Mostly in the center/right under the ribs where the cramp came on, but somewhat all over. I didn't notice this feeling in a single training session, though I did in my last race.
Sorry this is so long, but any ideas on how to overcome this problem would be greatly appreciated!