Had a colonoscopy a 2 week ago. a large polyp was removed 5 inches inside , no problems until last few days , very sore in the rectum , no blood .

Unlikely from poly: Polypectomies rarely cause pain. Some colon spasm can be present but typically in the first 1-2 days. At two weeks it is unlikely due to a injury through your colon wall either. If the pain is only present during a bowel movement it is likely an anal fissure. Constant pain and pressure can be diverticulitis and/or constipation. Stool softeners and a gradual increase in fiber intake may be helpful.

Getting better/worse: ?? if worse, would definitely go see your GI doc. did you get constipated after the procedure perhaps? sometimes straining can lead to more painful hemorrhoids. Make sure you know what your polyp was as well (tubular adenoma, tubulovilleous adenoma, any dysplastic changes) and when they want you back.