Can bloating and irregular bowel movements be a sign of colon cancer in a 27 year old male?
Based on your age and your 6 years of symptoms, and assuming you have no family history of colorectal cancers, the odds of your symptoms being due to a tumour are low.
However, a screening colonoscopy is still your best bet in excluding a potentially serious condition. Discuss with your GP to explore this option. Colonoscopy is still the gold standard and in trained hands a very safe and quick procedure.