you all scaring the nine lives out of me

i just started with this pain about 6 months ago asprin  makes the pain go away better then muscle relaxers and vicodin this pain is when you 1st get up like a stabbing dragging pain  then its gone dont hurt while im sitting  mostly standly up or going to sit down,i go in for a mri on wensday cause the pain hurts pretty good now more like a pain in the ass it surges  what are other types of things could i have wrong other then colon cancer