How To Treat Disc Herniation Radiculitis?

Hi, my husband had a back pain started 3 weeks ago. And last Thursday he was driving and had to pull over cause the pain was very bad. So I took him to a chiropractor and he wants my husband to get an MRI and a steroid shoots. After the shoots his back feels much better but his thigh is still in a lot of pain. After reviewing the MRI results the chiropractor said that he has a DISC HERNIATION RADICULITIS. Until now my husband is still taking ADVIL to reduce the pain.What would be the best treatment should he do at this stage?