Can gas cause leg pain when jogging?

Not usually. Leg pain while jogging is most commonly caused by weak knees, overweight and/or other straining in your knees. If you can't jog due to leg pain, I would recommend you use an elliptical machine. Elliptical machinery puts very little pressure to your leg joints which make the possibility for your knees to hurt smaller. If your leg pain continues, you should contact a medical professional.