I think the referral process takes about 5-6 weeks in the UK. My girlfriend has private healthcare which covers me so i can normally get an appointment within 24 hours.
I would suggest that you get a head start by asking your doctor to prescribe you rectogesic glyceryl trinitrate (GTN) - that way by the time you get a CRS appointment you will be well into your GTN course.
The GTN relaxes the internal sphincter muscle so will help ease the spasm pain.
My CRS is in central London - i thought you may have the same guy!