hi, more details are required. I think your friend had a blocked kidney
tube due to stones and so a tube has been put into her kidney from the flank to drain the kidney (called pcn tube). this is done to reverse the kidney swelling and prevent further kidney damage due to blocked kidney tube. It is also done in case the urine in kidney is infected or pus-like (pyonephrosis
or infected HN). If tube gets blocked, check that it is not getting twisted or kinked, it is not getting compressed while lying down. If still gets blocked, probably changing to a larger size tube will help. Her urologist
will be best person to help. good luck.