I think i may have a polyp. Have a small sack (which i think is a polyp) near my anis on the outside. It has been there for a while and i just thought it might be a hemmroid at first. Now im starting to worry because other signs are there. Blood on stool, very tired and now have pressure in the anis, bowels do look different and may be more frequent at times. I know i should get a colonoscopy, but im nervous about the outcome. How long does it usually take for polyps to get out of control and end up as cancer? First noticed some blood about 4 yrs ago and some once and a while but thought it was hemmoroids on the inside. Any feedback and support appreciated. Pressure increased since i have been worrying a few days on and off. Checked for blood on stool and didn't see any the last couple of days.