Unfortunately chiropractors are (usually well meaning) quacks based on pseudoscientific woo who, as was stated above, are better at billing than actually doing anything beneficial.
I'll have to update my business cards with this eloquent and obviously well informed opinion...
Modern chiro uses the manipulation as a gateway into rehabilitation, which serves as a gateway into strength and conditioning. The problem comes when people work under the assumption that when the pain is gone, the back must be "well", and fail to progress into the rehab and then strength and conditioning aspects (people are pretty much motivated by pain and when it's gone, so is the motivation to spend the time, effort, and money to actually solve the underlying problem). Not surprisingly, the condition then returns and the cycle usually continues, somewhat indefinitely... If you happen to go to a chiro who believes that adjustment is the only necessary component to get a back "well", find a new chiro IMO.
Say you have an electrical problem in your house that causes a fire. What do you do?
Step 1: call fire dept, to put out fire
Step 2: call electrician, to fix electrical problem
Step 3: call contractor to fix fire damage
If we only put out the current fire and don't fix the underlying problem, it's just a matter of time before we have another fire... Conversely, it's hard to fix the wiring when the house is still on fire.
So, in back pain:
Step 1: Reduce pain/symptoms (chiro, acu, med's, pt, etc... Different things work for different people)
Step 2: Restore function (this is the rehab part, teach the body to move more efficiently and to avoid injury mechanisms/patterns, hip based movement patterns and proper bracing are worth knowing and practicing)
Step 3: Rebuild strength with appropriate exercise selection and intelligent loading strategies.
Just like it's hard to fix the wiring when the house is on fire, it's difficult to teach the body to move well/better when there is significant pain in the picture.
If you only complete step 1, you're going to be completing it repeatedly, and with age, you can expect the condition to worsen throughout the 4th and 5th decades of life, and then usually get better and the spine naturally stabilizes itself (arthritis).
And... all of that does nothing to help you current situation in the immediate short term... Call the fire dept...