I had alot of shoulder pain also. Are you sure it is time for you to be on your mushie stage. I was on clear liquids a week, then full liquids a week and then the third week I could slowly introduce mushies. I also got pain when I drank too fast because it trapped addl air which was painful to burp. One thing I do know if you move through your stages too fast it will hurt you in the long run so take slow.... Each day will get better.