The Spasm of the muscle might occur because of many reasons. Common among them are inapropriate posture & decresed levels of serum calcium. So go through your life styl and try to recollect whether you are opting wrong and unhealthy posture which may be causing stress on your right sidede abdominal & back muscles. If this is the reason try to acquire correct posture by own or you may take help of physiotherapist who may help you to guid regarding your posture. you may apply local muscle relaxant creams as well & can have oral anti inflammatory + muscle relaxants agents as per physicians advice. One more thing I would like to advice is you should get your blood calcium level checked and may start on calcium suppliments too after getting reports.