OK then this is a serious situation potentially.
We screen for polyps and colon cancer at age 50, 60 and 70.
So you are way behind.
Possibilities here are Diverticulosis Irritable bowel Colitis Polyps Cancer.
I would arrange immediately for a colonoscopy as this will diagnose which it is.
If this pain continues and increases you need to go right to A and E.
Use reply to let me know if you have further questions. Please to not forget a positive rating.