No referral is required.
Some conditions only take one or two treatments to resolve (ie spinal joint sprain), however other more complex/chronic conditions (ie disc bulges) may require an on-goinging treatment plan (ie 6-8 treatments) to fully resolve.
Typically, you will not be required to remove clothing, however loose fitting clothing or bringin a pair of shorts may be helpful.
Treatment sessions last 30 minutes an involve a thorough history, examination & treatment. You will also be given specific advice on exercise & rehab regarding your conditions.