Qur symptoms and conditions

This is about my sister who was diagnosed with dermatomyositis about 1 month ago. She has been on prednisone ever since and just a few days ago started experiencing really bad stomach pain and back pain/burning on the left side. we took her to the e.r. where they ran a number of tests and didn't find anything wrong. i have been researching all her meds and can only come up with this: prednisone has to be the culprit. God bless all of you who have to take this drug for anything. I wish you all the best. It has been hard seeing her suffer, but without it her condition would not get better.