You can also try stretching to relieve the cramp. Most side stitches are on the right side, so raise your right hand and lean to the left to stretch. Do the opposite if your stitch is on the left side. When the stitch subsides, start walking, then slowly begin running and gradually pick up your pace.
Similarly, you may ask, what causes a stitch in side?
When running, there is increased abdominal pressure pushing up on the diaphragm. At the same time, rapid breathing causes the lungs to expand and this presses down on the diaphragm, a muscle that if “pinched” from above and below, gets less blood flow and spasms, resulting in painful side stitches.