Mine was discovered as I suffered extreme constipation for several weeks. I bit the bullet and reluctantly visited my GP. First test was a ultra scan which was as helpful as a chocolate teapot. The techie told me that the scan would not reach the area under investigation. I was then given the poo stick test, over three days, by the GP. That came back negative as did the previous tests I provided as part of the national screening programme from Northwick Park hospital.
Last chance was the colonoscopy and bingo it finished before it started. A tumour the size of an orange blocked the camera. A coupl of minor polyps cut out and a biopsy of the tumour taken. The rest is history but caught in time. :-) Last visit to my GP about 2 weeks ago, with regard to a cardio matter,she tried to interest me in the National screening programme.As she had taken over from a retired doctor I respectfully suggested she may like to refer to my notes on her computer in future as my episode of cancer was only about 5 years back. I also told her, politely but in no uncertain terms, what I thought of shoving a lollipop stick up one's rectum as a reliable indicator of my sigmoid cancer.