My mom is 48. She had colon cancer. Now her blood cea is 123 & rising. Previously she underwent colon & liver surgery & chemotherapy. Then there was pleural effusion & recently she is affected with pulmonary tb & taking anti-tb drugs. But, she is feeling severe pain from pelvic region to feet only in left leg! she is taking diclofenac potassium & myolax tablet. Can you tell me the cause of this pain? And how to treat it?