Hi

i had the 2 yearly bowel screening last October and like you had no symptoms at all. I am also of  the same age as yourself.  But blood was found in my poo sample so I was referred for a colonoscopy. I had this first week in December and unfortunately they found a tumour. I had a CT scan and blood samples taken the same day. I was then invited to a short notice clinic on 19th December and offered surgery 3 days later. I was in hospital for only 4 days coming out on  Boxing Day having had robotic surgery to remove the tumour. It was later diagnosed after the pathology tests as stage 3 and because out of 14 lymph nodes removed 1 had a single cancer cell  I was recommended to have 4 rounds of chemotherapy treatment over 3 months. I have just completed this. It is not pleasant but is nothing to be scared about.and I even managed to go to work around the treatment albeit on reduced hours. I am just thankful that it was found before it spread anywhere else in my body and was dealt with very quickly. 
 

However remember not all referrals necessarily mean cancer. My neighbour was also recently referred and his blood samples were the result of polyps which were removed at the time of the colonoscopy. So please do go and get checked and try not to worry.