After couple of persistent cin 1 over the years had a colposcopy where doctor found changes on the screen but said she would take a watch and wait approach. That was a year ago. So I went for colposcopy a year later and looking at the screen and after staining all previous changes had resolved themselves. I presume a smear was also done there as I then had a letter in the post a month or so later asking me to come for a lletz procedure due to high grade dyskaryosis. Why would colposcopy exam look clear but then I need a lletz a month later?