About 60% of athletes know what a side stitch feels like. It’s a stabbing pain in your gut that can bring you to a stand-still. Because getting attacked by a side stitch is unpredictable (that is, one day you might get one but the next day you don't), they are hard to research. The available data suggests they commonly occur in the same spot: on the upper right side of the abdomen where the liver is attached to the diaphragm by two ligaments.
To treat a side stitch, many athletes bend forward, stretch the affected side, breathe deeply from the belly, push up on the affected area, tighten the abdominal muscles, and/or change from "shallow" to "deep" breathing. (Pretend you are blowing out candles while exhaling with pursed lips.)
While we aren't 100 percent certain what causes a side stitch, the prevailing theory is exercise creates stress on the ligaments that connect the liver to the diaphragm. Stitches can be provoked by a heavy dose of pre-exercise food and fluids, minimal training and inadequate pre-exercise warm-up. Wearing a tight belt can help reduce organ jostling and reduce the symptoms. You could also record your food and fluid intake to try to detect triggers (too much pre-exercise water? too large a meal?). With repeated dietary tweaks, you can hopefully discover a tolerable portion of pre-exercise fuel, or at least start to train your body to be able to tolerate small amounts that can enhance your performance without sending you to the sidelines.
Eat wisely and play well,
Nancy Clark and Gloria Averbuch
Food Guide for Soccer: Tips and Recipes From the Pros
For more information on diestive concerns, see Chaper 9: Fueling Before Exercise in Food Guide for Soccer: Tips and Recipes From the Pros.