Hey! I was busy at work all day....
Anyway, just like any field, there are good MDs and bad ones, just like chiropractors. If chiropractic just isn't working, then by all means, explore other avenues. I would start with an MRI to see what's going on. One cortisone shot shouldn't kill ya, but usually they don't help much for low back pain. It may, however, take the edge off enough for the chiropractor, accupuncturist, physical therapist, and/or massage therapist to start doing some good.
It just depends on what the problem is, so I'd get an MRI if I were your friend. If nothings shows, then try a bunch of differnt treatments to find what works. If it is the disc, I would go with the chiro, sometimes it takes a bit more time to get over the hump (which the cortisone may do ... but don't get too many shots!!!).
Everyone is gonna say their treatment is the best, or course, so I'd start with least invasive to most invasive.
If your friend wants a consultation, he or she can certainly meet with me, I won't charge for talking with him/her.