My mother is having severe and persistent stomach pains between the upper abdomen and the chest. Blood and urine tests are o.k.

My mother have been in severe pains around the upper abdomen and chest since three weeks now. Both blood and urine tests has been conducted and there was nothing wrong. The sitiuation is now getting unbearable both for her and and the family. We don't know what to do to stop the pains. What pain killers and drugs can be bought from the pharmacy to assist her. The hospitals seems to be a too slow and without any convincing explanation to these problem. Please, kindly advise us on what to do???