Hello and Welcome to HCM,
Thanks for writing to us.
From description it seems he might be suffering from siatica. Sciatica
refers to pain that radiates along the path of the sciatic nerve
— which branches from your lower back through hips and buttocks and down each leg.
Although the pain associated with sciatica can be severe, most cases resolve with just conservative treatments in a few weeks.
MRI is needed to establish the cause of sciatica, so that appropriate treatment can be prescribed. Sciatica do respond well to bed rest
and analgesics (pain killer) and is right mode of treatment.
The definitive treatment depends upon the cause of sciatica. I would suggest him to consult an orthopediac surgeon who may order MRI to determine cause of sciatica (level and degree in case of disc herniation) and may suggest other mode of treatment. After initial few days of bed rest, he needs physiotherapy
Hope this helps you.
Wishing you good health...
Dr Saurabh Gupta.