Colonoscopy consultation?

Does anyone know what happens during a colonoscopy consultation? I was told by my doctor to have a colonoscopy scheduled asap. But is the consultaion the same as 'the colon prep' ?? If not, how long after is the actual colonoscopy preformed? I'm very stressed out about having the procedure done, and would just like to get it over with. I've had ulcerative colitis for over 5 years now, and i'm 23 years old. My symptom flare ups have gradually worsen, and i'm afraid that i may have colon cancer.