Hallo,
The reason for aking her to stick to bed rest for that period to permite the time and mechanism for healing process,and you should be careful not to let her to stick to bed 24 hours all day ,no she have to walk for about 7-10 minutes every one hour of her laying,thus we could prevent healing process in a wrong way,....
The causes for surgery:
1.The conservative treatment failed to relive pains,
2.Urinary incontinence(bladder and bowel control absent)!
Surgery not usually the perfect solution ,as in operations of disc prolabes surgoen will change(mostly decrease)stability of vertebra and quensecnetly pains back this is the nature of such operations not releated to best hands surgeon!
Hope this could help you,..you can ask your physician all questions you have as this your own right,