I'm 54 and diagnosed with Stage 4 colon cancer M1 Lungs. I'm concerned my GP didn't refer me to a cancer specialist or order colonoscopy/CT scan tests when I visited with specific concerns about bowel cancer (i.e. irregular bowel movements, darkened stool, unexplained persistent lower right back pain) a year before my caecal cancer diagnosis. What would prevent a GP from ordering such screening as soon as possible? How long does it take for a colon polyp to grow into a 5cm caecal carcenoma? How fast does bowel cancer spread to other organs after it penetrates the bowel wall?