What Is The Reason For Severe Leg And Back Pain?

Hi, my mother's age is 50 yrs , 62 weight and height 5 feet.She is having severe leg pain and back pain. The MRI of Lumbar spine report results is as follows "severe thecal sac stenosis at L4-5 level due to diffuse disc bulge with right foraminal encroachment and large central disc extrusion.Mild superior migration of extruded L4-5 disc is noted" Please suggest possible options for faster recovery. Thanks in advance