Can eating before exercise cause a stitch?

Yes, but scientists aren’t completely sure why. Stitches are thought to be caused by cramp in the diaphragm, which is connected to the spleen, liver and stomach by ligaments. When you exercise these organs move around and, if your stomach is full, this might cause pain. Another suggestion is that a full stomach could rub against the parietal peritoneum, a slippery covering that coats the organs in the abdomen, causing friction and discomfort.