Please don't panic as the doctor has just suggested one of the causes and because of that there are government guidelines that say you have to have an urgent referral.  The same for breast lumps and many other symptoms that need urgent referrals.  This does not mean she thinks its bowel cancer as there are lots of reasons for back passage bleeding, tears in the anus, enlarged veins that can burst when you pass a stool and will show bright red blood which is scary and obviously mixes in with the stools as they have to come out the same way.  I have had this and it was not bowel cancer and I was 60 years old and after a repair to my back passage I was fine.  We do have nurses on this forum call one of them for more advice and don't Google because it will point you in the wrong direction.  Good luck and look to your future as you are young and being seen soon.  Carol 

Thank you so much for your response. 
I have stayed away from google doctor and just waiting upon the actual Colonoscopy to tell me what's going on. I don't want to unnecessarily worry myself. 
Unfortunately it was my doctor that actually caused this worry. When asked what other things it could potentially be she said she pretty much ruled out a lot of other stuff and it was pointing more toward cancer. She did tell me it's rare for my age (I am 32) but highlighted that my symptoms were identical to that of someone with advanced bowel cancer so I've been out of my mind with worry since visiting her this morning. 
I have driven my husband crazy with trying to prepare for the worst.  

I'm sorry your doctor has said this,  it would have been kinder to have the colonoscooy and then discuss the proper results.  No wonder you are so upset and scared, I would be as well.  If you're uo to it let us know how it goes and I'll keep following your thread.  Just remember that the nurses on this forum are a big help and comfort so call them if you need more help.  Love Carol x 

Thank you so much. I shall keep you updated. I'm trying my best to think positive but I'd be lying if I said I wasn't absolutely petrified. Fingers crossed the appointment happens quickly xx